diff --git a/src/common/time.cpp b/src/common/time.cpp
index 9161140e2..a81466ab7 100644
--- a/src/common/time.cpp
+++ b/src/common/time.cpp
@@ -22,10 +22,16 @@
 
 
 #include "common/time.hpp"
+#include <limits>
+
 
 namespace cinelerra
   {
 
+   // TODO: dummy values; should be adjusted when switching to the real time implementation provided by the backend
+  
+   const Time Time::MAX = std::numeric_limits<long>::max();
+   const Time Time::MIN = -MAX;
 
 
 } // namespace cinelerra
diff --git a/src/common/time.hpp b/src/common/time.hpp
index 1e94effb7..482f074c9 100644
--- a/src/common/time.hpp
+++ b/src/common/time.hpp
@@ -24,6 +24,7 @@
 #ifndef CINELERRA_TIME_H
 #define CINELERRA_TIME_H
 
+#include <boost/operators.hpp>
 
 
 namespace cinelerra
@@ -38,13 +39,22 @@ namespace cinelerra
    *       elaborate timehandling functions in the backend and the goal
    *       is for class Time to be just a thin wrapper!
    */
-  class Time
+  class Time : boost::totally_ordered<Time>
     {
       long dummy;
     public:
       Time(long dum=0) : dummy(dum) {}
       operator long () { return dummy; }
+      
+      bool operator<  (const Time& ot)  const { return dummy <  ot.dummy; }
+      bool operator== (const Time& ot)  const { return dummy == ot.dummy; }
+      
+      static const Time MAX ; 
+      static const Time MIN ;
     };
+    
+  
 
+   
 } // namespace cinelerra
 #endif
diff --git a/src/common/util.hpp b/src/common/util.hpp
index 2e9f3dac9..3d465f666 100644
--- a/src/common/util.hpp
+++ b/src/common/util.hpp
@@ -165,6 +165,6 @@ namespace util
 /** shortcut for subclass test, intended for assertions only.
  *  @note it is considered bad style to use such in non-assertion code,
  *        and we probably will enforce this design rule in future. */
-#define INSTANCEOF(CLASS, EXPR) (dynamic_cast<CLASS*> (EXPR)) 
+#define INSTANCEOF(CLASS, EXPR) (dynamic_cast<const CLASS*> (EXPR)) 
 
 #endif /*UTIL_HPP_*/
diff --git a/src/proc/asset/category.hpp b/src/proc/asset/category.hpp
index b51ef1919..6b36e467b 100644
--- a/src/proc/asset/category.hpp
+++ b/src/proc/asset/category.hpp
@@ -78,6 +78,7 @@ namespace asset
         
       bool hasKind (Kind refKind)     const         { return kind_ == refKind; }
       bool isWithin (const Category&) const;
+      void setPath (const string & newpath)         { this->path_ = newpath; }
       
       
       operator string ()  const;
diff --git a/src/proc/asset/clip.cpp b/src/proc/asset/clip.cpp
index dc46f96d7..72d2605ba 100644
--- a/src/proc/asset/clip.cpp
+++ b/src/proc/asset/clip.cpp
@@ -26,6 +26,47 @@
 namespace asset
   {
   
+  namespace
+    {
+      /** @internal derive a sensible asset ident tuple
+       *  when creating a asset::Clip based on some asset::Media
+       *  @todo getting this one is important for handling creation
+       *        of multiple clip instances from one media. Means we
+       *        have still to figure out a sensible concept...
+       */
+      const Asset::Ident
+      createClipIdent (const Media& mediaref)
+        {
+          string name (mediaref.ident.name + "-clip");  // TODO something sensible here; append number, sanitize etc.
+          Category category (mediaref.ident.category);
+          category.setPath(CLIP_SUBFOLDER);
+          return Asset::Ident (name, category, 
+                               mediaref.ident.org, 
+                               mediaref.ident.version );
+          
+        }
+      
+      Media::PClipMO
+      createClipMO (const ID<Media>& mediaID)
+        {
+          return mobject::MObject::create(
+                     AssetManager::instance()
+                               .getAsset (mediaID));
+        }
+    }
+  
+  
+  
+  Clip::Clip (const Media& mediaref)
+    : Media (createClipIdent (mediaref),
+             mediaref.getFilename())
+    , source_ (mediaref) 
+    , clipMO_ (createClipMO (this->getID()))
+  {
+    
+  }
+  
+  
   /** Directly object creating specialisation of the 
    *  asset::Media interface method: immediately starting
    *  out from this asset::Clip and doing the actual 
@@ -35,12 +76,12 @@ namespace asset
   Media::PClipMO 
   Clip::createClip ()
   {
-    if (!this.clipMO_)
-      this.clipMO_ = MObject::create(
-                       AssetManager::instance()
-                          .getAsset (this.getID()));
+    if (!clipMO_)
+      clipMO_ = mobject::MObject::create(
+                  AssetManager::instance()
+                     .getAsset (this->getID()));
     
-    return this.clipMO_;
+    return clipMO_;
   }
   
   
@@ -51,7 +92,7 @@ namespace asset
   Clip::getClipAsset ()
   {
     return PClip (AssetManager::instance()
-                    .getAsset (this.getID()));
+                    .getAsset (this->getID()));
   }
   
   
@@ -61,7 +102,7 @@ namespace asset
   Media::PMedia
   Clip::checkCompound ()
   {
-    return this.source_.checkCompound();
+    return source_.checkCompound();
   }
 
 
diff --git a/src/proc/asset/clip.hpp b/src/proc/asset/clip.hpp
index e39ae34eb..0e01fdb63 100644
--- a/src/proc/asset/clip.hpp
+++ b/src/proc/asset/clip.hpp
@@ -38,21 +38,26 @@ namespace asset
       /** media source of this clip  */
       const Media& source_;
       
-      /** the corresponding (dependant) clip-MO */
+      /** the corresponding (dependant) clip-MO 
+       *  @todo seems to be obsolete by the reworked design of multichannel media 11/07 */
       PClipMO clipMO_;
       
     public:
       virtual PClipMO createClip ();
       virtual PMedia checkCompound ();
       
-    private:
-      Clip (const Media& mediaref) : source_(mediaref) {};
+    protected:
+      Clip (const Media& mediaref);
       friend class MediaFactory;
       
       virtual PClip getClipAsset ();
 
     };
     
+    typedef shared_ptr<const asset::Clip> PClipAsset;
+    
+    const string CLIP_SUBFOLDER = "clips";      // TODO: handling of hard-wired constants....
+    
     
     
 } // namespace asset
diff --git a/src/proc/asset/media.cpp b/src/proc/asset/media.cpp
index c88bdbfc0..d4a4bb00f 100644
--- a/src/proc/asset/media.cpp
+++ b/src/proc/asset/media.cpp
@@ -90,7 +90,7 @@ namespace asset
   
   
   Media::PMedia
-  Media::checkCompound()
+  Media::checkCompound()  const
   {
     PAsset parents = this.getParents();
     PMedia parent(0);
diff --git a/src/proc/asset/media.hpp b/src/proc/asset/media.hpp
index 7e2f92178..e60b8274b 100644
--- a/src/proc/asset/media.hpp
+++ b/src/proc/asset/media.hpp
@@ -38,7 +38,7 @@
 #include "proc/asset.hpp"
 #include "common/factory.hpp"
 #include "proc/mobject/mobject.hpp"
-
+#include "proc/mobject/session/clip.hpp"
 
 
 
@@ -72,7 +72,7 @@ namespace asset
       typedef shared_ptr<Media> PMedia;
       typedef shared_ptr<const asset::Clip> PClip;
       typedef shared_ptr<asset::ProcPatt> PProcPatt;
-      typedef mobject::Placement<mobject::session::Clip> PClipMO;
+      typedef mobject::session::PClipMO PClipMO;
      
       
       static MediaFactory create;
@@ -111,7 +111,7 @@ namespace asset
        *  is part of a compound (multichannel) media.
        *  @return pointer to parent, or \code null
        */
-      virtual PMedia checkCompound ();
+      virtual PMedia checkCompound ()  const;
 
     };
     
diff --git a/src/proc/mobject/explicitplacement.hpp b/src/proc/mobject/explicitplacement.hpp
index 8896405a7..5a86d71ec 100644
--- a/src/proc/mobject/explicitplacement.hpp
+++ b/src/proc/mobject/explicitplacement.hpp
@@ -49,6 +49,8 @@ namespace mobject
     public:
       const Time time;
       const Track track;
+      
+      typedef std::pair<Time,Track> SolutionData;  //TODO (ichthyo consideres better passing of solution by subclass)
 
       /** no need to resolve any further, as this ExplicitPlacement
        *  already \i is the result of a resolve()-call.
@@ -66,12 +68,12 @@ namespace mobject
        *        be initialized directly here in the ExplicitPlacement ctor. 
        *        (ichthyo: siehe Trac #100)
        */
-      ExplicitPlacement (Placement<MObject>& base, const session::FixedLocation found)
-        : Placement(base),
-          time(found.time_), track(found.track_)
+      ExplicitPlacement (const Placement<MObject>& base, const SolutionData found)
+        : Placement<MObject>(base),
+          time(found.first), track(found.second)
         { };
         
-      friend ExplicitPlacement::resolve () const;
+      friend ExplicitPlacement Placement<MObject>::resolve () const;
     };
 
 
diff --git a/src/proc/mobject/mobject.cpp b/src/proc/mobject/mobject.cpp
index 284d12f9c..6b775d206 100644
--- a/src/proc/mobject/mobject.cpp
+++ b/src/proc/mobject/mobject.cpp
@@ -22,7 +22,7 @@
 
 
 #include "proc/mobject/mobject.hpp"
-#include "proc/mobject/placement.hpp"
+#include "proc/mobject/session/mobjectfactory.hpp"
 
 namespace mobject
   {
diff --git a/src/proc/mobject/mobject.hpp b/src/proc/mobject/mobject.hpp
index 1e18e09e8..252d9cf5c 100644
--- a/src/proc/mobject/mobject.hpp
+++ b/src/proc/mobject/mobject.hpp
@@ -64,8 +64,11 @@ namespace mobject
       // TODO: how to represent time intervals best?
       Time length;
       
+      MObject() {}
       virtual ~MObject() {};
       
+      friend class session::MObjectFactory;
+      
     public:
       static session::MObjectFactory create;
       
@@ -77,7 +80,6 @@ namespace mobject
     };
   
   
-  typedef Placement<MObject> PMO;
   
 
 
diff --git a/src/proc/mobject/placement.hpp b/src/proc/mobject/placement.hpp
index 36fc216f9..62fa8e539 100644
--- a/src/proc/mobject/placement.hpp
+++ b/src/proc/mobject/placement.hpp
@@ -58,7 +58,7 @@
 #define MOBJECT_PLACEMENT_H
 
 #include "cinelerra.h"
-#include "proc/mobject/session/abstractmo.hpp"
+#include "proc/mobject/mobject.hpp"
 #include "proc/mobject/session/locatingpin.hpp"
 #include "proc/mobject/session/track.hpp"
 
@@ -68,11 +68,13 @@ using std::tr1::shared_ptr;
 
 namespace mobject
   {
+  namespace session{ class MObjectFactory; }
 
-  class MObject;
   class ExplicitPlacement;
+  
 
   
+  
   /**
    * A refcounting Handle to an MObject of type MO,
    * used to constrain or explicitly specify the
@@ -95,8 +97,8 @@ namespace mobject
       virtual MO * 
       operator-> ()  const 
         { 
-          ENSURE (this.get()); 
-          return shared_ptr::operator-> (); 
+          ENSURE (*this); 
+          return shared_ptr<MO>::operator-> (); 
         }      
       
       
@@ -110,80 +112,30 @@ namespace mobject
        *  by the various LocatingPin (\see #chain) and
        *  provide the resulting (explicit) placement.
        */
-      virtual ExplicitPlacement
-      resolve ()  const 
-        { 
-          return ExplicitPlacement (*this, chain.resolve()); 
-        }
+      virtual ExplicitPlacement resolve ()  const; 
       
       
     protected:
       virtual ~Placement() {};
-      Placement (MO & subject) 
-        : shared_ptr (&subject, &session::AbstractMO::destroy) {};
+      Placement (MO & subject, void (*moKiller)(MO*)) 
+        : shared_ptr<MO> (&subject, moKiller) {};
+        
+      friend class session::MObjectFactory;
     };
   
-
-  /* === defining specialisations to be subclasses === */  
+  typedef Placement<MObject> PMO;
+  
+  
+  
+  
+  /* === defining specialisations to be subclasses === */
+  
     
-  namespace session
-    {
-    class Clip;
-    class Effect;
-    class Meta;
-    }
   
   
-  template<>
-  class Placement<session::Clip> : public Placement<MObject>
-    { 
-      Placement (session::Clip & c) 
-        : Placement<MObject>::Placement (c) 
-        { };
-        
-    public:
-      virtual session::Clip*
-      operator-> ()  const 
-        { 
-          ENSURE (INSTANCEOF(session::Clip, this.get()));
-          return static_cast<session::Clip*> (shared_ptr::operator-> ()); 
-        }      
-    };
+  /////TODO: define Macro for specialisations here
   
   
-  template<>
-  class Placement<session::Effect> : public Placement<MObject>
-    { 
-      Placement (session::Effect & e) 
-        : Placement<MObject>::Placement (e) 
-        { };
-        
-    public:
-      virtual session::Effect*
-      operator-> ()  const 
-        { 
-          ENSURE (INSTANCEOF(session::Effect, this.get()));
-          return static_cast<session::Effect*> (shared_ptr::operator-> ()); 
-        }      
-    };
-  
-  
-  template<>
-  class Placement<session::Meta> : public Placement<MObject>
-    { 
-      Placement (session::Meta & m) 
-        : Placement<MObject>::Placement (m) 
-        { };
-        
-    public:
-      virtual session::Meta*
-      operator-> ()  const 
-        { 
-          ENSURE (INSTANCEOF(session::Meta, this.get()));
-          return static_cast<session::Meta*> (shared_ptr::operator-> ()); 
-        }      
-    };
-  
   /* a note to the maintainer: please don't add any fields or methods to
    * these subclasses which aren't also present in Placement<MObject>!
    * Placements are frequently treated like values and thus slicing
diff --git a/src/proc/mobject/session.hpp b/src/proc/mobject/session.hpp
index b83affe14..6bbe665f5 100644
--- a/src/proc/mobject/session.hpp
+++ b/src/proc/mobject/session.hpp
@@ -84,9 +84,9 @@ namespace mobject
     public:
       static session::SessManager& current;
       
-      virtual bool isValid ()               = 0;
-      virtual void add (PPla& placement)    = 0;
-      virtual bool remove (PPla& placement) = 0;
+      virtual bool isValid ()              = 0;
+      virtual void add (PMO& placement)    = 0;
+      virtual bool remove (PMO& placement) = 0;
       
       /// @deprecated Ichthyo doubts it is good design to hand out the EDL??
       virtual session::EDL& currEDL ()     = 0;
diff --git a/src/proc/mobject/session/abstractmo.hpp b/src/proc/mobject/session/abstractmo.hpp
index f73661d8a..d98bfd324 100644
--- a/src/proc/mobject/session/abstractmo.hpp
+++ b/src/proc/mobject/session/abstractmo.hpp
@@ -34,10 +34,12 @@ namespace mobject
     {
 
 
+    /**
+     *  abstract base class of all MObjects for providing common services.
+     *  @todo seems that we don't need this intermediate class...
+     */
     class AbstractMO : public MObject
       {
-        ////////////// TODO: work out common services to provide!!!!
-        shared_ptr<Placement> placement_;
         
       public:
         
@@ -45,13 +47,6 @@ namespace mobject
         
         virtual Time& getLength() { return length; }
         
-      protected:
-        /** custom deleter func allowing class Placement 
-          *  to take ownership of MObjct instances
-          */
-        static void destroy (MObject* o) { delete o; }
-        
-        friend class Placement;
 
      };
 
diff --git a/src/proc/mobject/session/allocation.hpp b/src/proc/mobject/session/allocation.hpp
index 209fc9406..dc8cd5191 100644
--- a/src/proc/mobject/session/allocation.hpp
+++ b/src/proc/mobject/session/allocation.hpp
@@ -55,7 +55,7 @@ namespace mobject
       public:
         const string& getRepr () const { return repr; }
         
-        virtual LocatingPin* clone ()  const = 0;
+        virtual Allocation* clone ()  const = 0;
       };
 
 
diff --git a/src/proc/mobject/session/clip.cpp b/src/proc/mobject/session/clip.cpp
index 8314b13f6..499567af5 100644
--- a/src/proc/mobject/session/clip.cpp
+++ b/src/proc/mobject/session/clip.cpp
@@ -35,7 +35,7 @@ namespace mobject
       : start_(0),
         mediaDef_(mediaDef)
     {
-      this.setupLength();
+      setupLength();
     }
     
     
diff --git a/src/proc/mobject/session/clip.hpp b/src/proc/mobject/session/clip.hpp
index 1a39cb14f..c58cfac3f 100644
--- a/src/proc/mobject/session/clip.hpp
+++ b/src/proc/mobject/session/clip.hpp
@@ -25,15 +25,22 @@
 #define MOBJECT_SESSION_CLIP_H
 
 #include "proc/mobject/session/abstractmo.hpp"
-#include "proc/mobject/placement.hpp"
 
 
+namespace asset
+  {
+    class Media;
+    class Clip;
+    typedef shared_ptr<const asset::Clip> PClipAsset;
+  }
 
 namespace mobject
   {
   namespace session
     {
     using asset::Media;
+    using asset::PClipAsset;
+    typedef shared_ptr<Media> PMedia;
 
 
     /**
@@ -52,7 +59,7 @@ namespace mobject
       {
       protected:
         /** startpos in source */
-        Time start;
+        Time start_;
 
         //TODO: where to put the duration ???
         
@@ -68,19 +75,40 @@ namespace mobject
         virtual bool isValid()  const;
         
         /** access the underlying media asset */
-        virtual Media::PMedia getMedia ()                        
+        virtual PMedia getMedia ()                        
           { 
             UNIMPLEMENTED ("how to relate MObjects and media assets...");
-            return AssetManager::instance().getAsset(IDA(0)); // KABOOM! (just to make it compile)
+            //return AssetManager::instance().getAsset(IDA(0)); // KABOOM! (just to make it compile)
           }
         
       };
       
-
+    typedef Placement<Clip> PClipMO;
 
 
 
   } // namespace mobject::session
+  
+  
+  ///////////////////////////TODO use macro for specialsation...
+  template<>
+  class Placement<session::Clip> : public Placement<MObject>
+    { 
+    protected:
+      Placement (session::Clip & m, void (*moKiller)(MObject*)) 
+        : Placement<MObject>::Placement (m, moKiller) 
+        { };
+      friend class session::MObjectFactory;
+        
+    public:
+      virtual session::Clip*
+      operator-> ()  const 
+        { 
+          ENSURE (INSTANCEOF(session::Clip, &(*this)));
+          return static_cast<session::Clip*> (shared_ptr<MObject>::operator-> ()); 
+        }      
+    };
+    
 
 } // namespace mobject
 #endif
diff --git a/src/proc/mobject/session/edl.cpp b/src/proc/mobject/session/edl.cpp
index 4b577e059..bad6ad185 100644
--- a/src/proc/mobject/session/edl.cpp
+++ b/src/proc/mobject/session/edl.cpp
@@ -35,13 +35,13 @@ namespace mobject
      *              to have this on the interface
      */
     bool 
-    EDL::contains (const PPla& placement)
+    EDL::contains (const PMO& placement)
     {
       UNIMPLEMENTED ("test if a given placement is contained within this EDL");
     }
     
     
-    PPla& 
+    PMO& 
     EDL::find (const string& id)
     {
       UNIMPLEMENTED ("serch for a given 'thing' within the EDL");
diff --git a/src/proc/mobject/session/edl.hpp b/src/proc/mobject/session/edl.hpp
index 24a7a136f..82222958f 100644
--- a/src/proc/mobject/session/edl.hpp
+++ b/src/proc/mobject/session/edl.hpp
@@ -48,8 +48,8 @@ namespace mobject
         vector<MObject *> clips;
 
       public:
-        bool contains (const PPla& placement);
-        PPla& find (const string& id); ///< @todo how to refer to clips? using asset IDs??
+        bool contains (const PMO& placement);
+        PMO& find (const string& id); ///< @todo how to refer to clips? using asset IDs??
         
         vector<PAsset>& getTracks () { return tracks; } ///< @todo use track assets correct, make const!
         size_t size ()
diff --git a/src/proc/mobject/session/effect.hpp b/src/proc/mobject/session/effect.hpp
index 09ed321bf..b79ba2f93 100644
--- a/src/proc/mobject/session/effect.hpp
+++ b/src/proc/mobject/session/effect.hpp
@@ -50,5 +50,22 @@ namespace mobject
      
   } // namespace mobject::session
 
+  ///////////////////////////TODO use macro for specialsation...
+  template<>
+  class Placement<session::Effect> : public Placement<MObject>
+    { 
+      Placement (session::Effect & m, void (*moKiller)(MObject*)) 
+        : Placement<MObject>::Placement (m, moKiller) 
+        { };
+        
+    public:
+      virtual session::Effect*
+      operator-> ()  const 
+        { 
+          ENSURE (INSTANCEOF(session::Effect, &(*this)));
+          return static_cast<session::Effect*> (shared_ptr<MObject>::operator-> ()); 
+        }      
+    };
+    
 } // namespace mobject
 #endif
diff --git a/src/proc/mobject/session/fixedlocation.cpp b/src/proc/mobject/session/fixedlocation.cpp
index 0a6753a71..e12205ec4 100644
--- a/src/proc/mobject/session/fixedlocation.cpp
+++ b/src/proc/mobject/session/fixedlocation.cpp
@@ -28,8 +28,8 @@ namespace mobject
   namespace session
     {
 
-    LocatingPin* 
-    LocatingPin::clone ()
+    FixedLocation* 
+    FixedLocation::clone ()  const
     { 
       return new FixedLocation (*this); 
     }
@@ -42,12 +42,12 @@ namespace mobject
       LocatingPin::intersect (solution);
       
       TODO ("either set position or make overconstrained");
-      if (solution.minTime <= this.time_)
-        solution.minTime = this.time_;
+      if (solution.minTime <= this->time_)
+        solution.minTime = this->time_;
       else
         solution.impo = true;
-      if (solution.maxTime >= this.time_)
-        solution.maxTime = this.time_;
+      if (solution.maxTime >= this->time_)
+        solution.maxTime = this->time_;
       else
         solution.impo = true;
     }
diff --git a/src/proc/mobject/session/fixedlocation.hpp b/src/proc/mobject/session/fixedlocation.hpp
index ca7254991..b509765de 100644
--- a/src/proc/mobject/session/fixedlocation.hpp
+++ b/src/proc/mobject/session/fixedlocation.hpp
@@ -51,11 +51,12 @@ namespace mobject
         
       protected:
         FixedLocation (Time ti, Track tra) : time_(ti), track_(tra) {};
+        friend class LocatingPin;
         
         virtual void intersect (LocatingSolution&)  const;
         
       public:
-        virtual LocatingPin* clone ()  const;
+        virtual FixedLocation* clone ()  const;
         
       };
 
diff --git a/src/proc/mobject/session/locatingpin.cpp b/src/proc/mobject/session/locatingpin.cpp
index 1404853ee..885018bfe 100644
--- a/src/proc/mobject/session/locatingpin.cpp
+++ b/src/proc/mobject/session/locatingpin.cpp
@@ -31,7 +31,7 @@ namespace mobject
   namespace session
     {
     inline LocatingPin*
-    cloneChain (scoped_ptr<LocatingPin>& chain)
+    cloneChain (const scoped_ptr<LocatingPin>& chain)
     {
       if (!chain) 
         return 0;
@@ -51,14 +51,14 @@ namespace mobject
     LocatingPin& 
     LocatingPin::operator= (const LocatingPin& other)
     {
-      if (this!=other) 
-        this.next_.reset (cloneChain (other.next_));
+      if (this != &other) 
+        this->next_.reset (cloneChain (other.next_));
       return *this;
     }
     
     
     LocatingPin* 
-    LocatingPin::clone ()
+    LocatingPin::clone ()  const
     {
       return new LocatingPin(*this);
     }
@@ -76,8 +76,8 @@ namespace mobject
       else
         {
           scoped_ptr<LocatingPin> tmp_next (newLp);
-          tmp_next->next_.swap(this.next_);
-          this.next_.swap(tmp_next);
+          tmp_next->next_.swap(next_);
+          next_.swap(tmp_next);
           return *newLp;
         }
     }
@@ -93,12 +93,12 @@ namespace mobject
      *  @todo we are packing and unpacking the information (time,track)
      *        several times. Ichthyo considers a more elegant solution.
      */
-    const FixedLocation
+    const LocatingPin::SolutionData
     LocatingPin::resolve ()  const
     {
       LocatingSolution solution;
       resolve (solution);
-      return FixedLocation (solution.getTime(), solution.getTrack());
+      return SolutionData (solution.getTime(), solution.getTrack());
     }
     
     bool 
@@ -109,22 +109,15 @@ namespace mobject
       return solution.is_impossible(); 
     }
 
-    
-    inline bool
-    still_to_solve (LocatingPin::LocatingSolution& solution) 
-    { 
-      return !(solution.is_definite() || solution.is_impossible()); 
-    }
-    
+
     
     void 
     LocatingPin::resolve (LocatingSolution& solution)  const
     {
-      if (!still_to_solve(solution)) 
+      if (!solution.still_to_solve()) 
         return;
-      this.intersect (solution);
-      if (this.next_ && 
-          still_to_solve (solution))
+      this->intersect (solution);
+      if (next_ && solution.still_to_solve())
         next_->resolve(solution);
     }
     
@@ -132,7 +125,7 @@ namespace mobject
     void 
     LocatingPin::intersect (LocatingSolution& solution)  const
     {
-      REQUIRE (still_to_solve (solution));
+      REQUIRE (solution.still_to_solve());
       // base class Implementation is NOP...
     }
     
@@ -170,6 +163,14 @@ namespace mobject
       return impo;
     }
     
+    bool
+    LocatingPin::LocatingSolution::still_to_solve () 
+    { 
+      return !(is_definite() || is_impossible()); 
+    }
+    
+    
+    
     
     
 
@@ -178,18 +179,18 @@ namespace mobject
     /* === Factory functions for adding LocatingPins === */
     
     FixedLocation&    
-    LocatingPin::operator() (Time, Track)
+    LocatingPin::operator() (Time start, Track track)
     {
       return static_cast<FixedLocation&> 
-                (this.addChain (new FixedLocation (Time, Track)));
+                (addChain (new FixedLocation (start, track)));
     }
     
     
     RelativeLocation& 
-    LocatingPin::operator() (PMO refObj, Time offset=0)
+    LocatingPin::operator() (PMO refObj, Time offset)
     {
       return static_cast<RelativeLocation&> 
-                (this.addChain (new RelativeLocation (Time, Track)));
+                (addChain (new RelativeLocation (refObj, offset)));
     }
     
     
diff --git a/src/proc/mobject/session/locatingpin.hpp b/src/proc/mobject/session/locatingpin.hpp
index 431ef5ef3..c01a4a295 100644
--- a/src/proc/mobject/session/locatingpin.hpp
+++ b/src/proc/mobject/session/locatingpin.hpp
@@ -44,6 +44,7 @@
 
 #include "cinelerra.h"
 
+#include <utility>
 #include <boost/scoped_ptr.hpp>
 using boost::scoped_ptr;
 
@@ -51,13 +52,17 @@ using boost::scoped_ptr;
 
 namespace mobject
   {
+  class MObject;
   template<class MO> class Placement;
+  typedef Placement<MObject> PMO;
 
   namespace session
     {
     class FixedLocation;
     class RelativeLocation;
     
+    class Track; //TODO
+    
     
     /**
      * Positioning specification, possibliy chained
@@ -76,6 +81,8 @@ namespace mobject
       protected:
         typedef cinelerra::Time Time;
         typedef session::Track* Track;
+        typedef std::pair<Time,Track> SolutionData;  //TODO (ichthyo consideres better passing of solution by subclass)
+        struct LocatingSolution;
       
         /** next additional Pin, if any */
         scoped_ptr<LocatingPin> next_;
@@ -88,12 +95,12 @@ namespace mobject
         virtual void intersect (LocatingSolution&)  const;
         
       public:
-        const FixedLocation resolve ()  const;
+        const SolutionData resolve ()  const;
         bool isOverdetermined () const;
         
         /* Factory functions for adding LocatingPins */
         
-        FixedLocation&    operator() (Time, Track=0);
+        FixedLocation&    operator() (Time start, Track track=0);
         RelativeLocation& operator() (PMO refObj, Time offset=0);
         
         LocatingPin (const LocatingPin&);
@@ -104,6 +111,8 @@ namespace mobject
       protected:
         LocatingPin () {};
         
+        friend class Placement<MObject>;
+        
         /** 
          * @internal helper for the (preliminary)
          * position resolve() implementation.
@@ -121,18 +130,20 @@ namespace mobject
             bool impo;
             
             LocatingSolution () 
-              : minTime(-1e15),  // TODO: better implementation of "unspecified..."
-                maxTime(+1e15),
+              : minTime(Time::MAX),  // TODO: better implementation of "unspecified..."
+                maxTime(Time::MIN),
                 minTrack(0),     // TODO
                 maxTrack(0),
                 impo(false)
               { }
             
-            Time getTime();
-            Track getTrack();
+            Time getTime ();
+            Track getTrack ();
+            
+            bool is_definite ();
+            bool is_impossible ();
+            bool still_to_solve (); 
             
-            bool is_definite();
-            bool is_impossible();
           };
       };
       
diff --git a/src/proc/mobject/session/meta.hpp b/src/proc/mobject/session/meta.hpp
index 8c141f516..e41231e2c 100644
--- a/src/proc/mobject/session/meta.hpp
+++ b/src/proc/mobject/session/meta.hpp
@@ -48,6 +48,23 @@ namespace mobject
 
 
   } // namespace mobject::session
+  
+  //////////////////////////////////TODO
+  template<>
+  class Placement<session::Meta> : public Placement<MObject>
+    { 
+      Placement (session::Meta & m, void (*moKiller)(MObject*)) 
+        : Placement<MObject>::Placement (m, moKiller) 
+        { };
+        
+    public:
+      virtual session::Meta*
+      operator-> ()  const 
+        { 
+          ENSURE (INSTANCEOF(session::Meta, &(*this)));
+          return static_cast<session::Meta*> (shared_ptr<MObject>::operator-> ()); 
+        }      
+    };
 
 } // namespace mobject
 #endif
diff --git a/src/proc/mobject/session/mobjectfactory.cpp b/src/proc/mobject/session/mobjectfactory.cpp
index 740852558..8726a28b3 100644
--- a/src/proc/mobject/session/mobjectfactory.cpp
+++ b/src/proc/mobject/session/mobjectfactory.cpp
@@ -48,7 +48,7 @@ namespace mobject
     Placement<Clip>   
     MObjectFactory::operator() (PClipAsset& mediaDef)
     {
-      return Placement<Clip> (new Clip (mediaDef));
+      return Placement<Clip> (*new Clip (mediaDef), &deleterFunc);
     }
     
     
diff --git a/src/proc/mobject/session/mobjectfactory.hpp b/src/proc/mobject/session/mobjectfactory.hpp
index cca272ff3..7d7130b5b 100644
--- a/src/proc/mobject/session/mobjectfactory.hpp
+++ b/src/proc/mobject/session/mobjectfactory.hpp
@@ -46,11 +46,15 @@ namespace mobject
 
     class MObjectFactory
       {
-      public:
-        typedef Placement PType;
+        /** custom deleter func allowing class Placement 
+          *  to take ownership of MObjct instances
+          */
+        static void deleterFunc (MObject* o) { delete o; }
         
-        PType<Clip>   operator() (PClipAsset&);
-        PType<Effect> operator() (const asset::Effect);
+      public:
+        
+        Placement<Clip>   operator() (PClipAsset&);
+        Placement<Effect> operator() (const asset::Effect);
         
       };
 
diff --git a/src/proc/mobject/session/relativelocation.cpp b/src/proc/mobject/session/relativelocation.cpp
index 7439a9913..df4f53fca 100644
--- a/src/proc/mobject/session/relativelocation.cpp
+++ b/src/proc/mobject/session/relativelocation.cpp
@@ -29,8 +29,8 @@ namespace mobject
   namespace session
     {
 
-    LocatingPin* 
-    LocatingPin::clone ()
+    RelativeLocation* 
+    RelativeLocation::clone ()  const
     { 
       return new RelativeLocation (*this); 
     }
diff --git a/src/proc/mobject/session/relativelocation.hpp b/src/proc/mobject/session/relativelocation.hpp
index eca3d9e24..5e1607029 100644
--- a/src/proc/mobject/session/relativelocation.hpp
+++ b/src/proc/mobject/session/relativelocation.hpp
@@ -38,6 +38,8 @@ namespace mobject
 
     class RelativeLocation : public LocatingPin
       {
+        const PMO & anchor_;  ////////////TODO: ooooops, this is a nasty design problem!!!
+        
       public:
 
         /**
@@ -49,13 +51,14 @@ namespace mobject
         };
 
       protected:
-        Placement anchor;  ////////////TODO: ooooops, this is a nasty design problem!!!
+        RelativeLocation (const PMO& a, Time ofs) : anchor_(a), offset_(ofs) { }
+        friend class LocatingPin;
 
         /** the kind of relation denoted by this Placement */
         RelType relType;
 
         /** Offset the actual position by this (time) value relative to the anchor point. */
-        Time offset;
+        Time offset_;
         //TODO: suitable representation?
         
         
@@ -63,7 +66,7 @@ namespace mobject
         
         
       public:
-        virtual LocatingPin* clone ()  const;
+        virtual RelativeLocation* clone ()  const;
 
       };
 
diff --git a/src/proc/mobject/session/sessionimpl.cpp b/src/proc/mobject/session/sessionimpl.cpp
index 056732116..e4dfec881 100644
--- a/src/proc/mobject/session/sessionimpl.cpp
+++ b/src/proc/mobject/session/sessionimpl.cpp
@@ -74,14 +74,14 @@ namespace mobject
     
     
     void 
-    SessionImpl::add (PPla& placement)
+    SessionImpl::add (PMO& placement)
     {
       UNIMPLEMENTED ("add Placement to the current EDL");
     }
     
     
     bool 
-    SessionImpl::remove (PPla& placement)
+    SessionImpl::remove (PMO& placement)
     {
       UNIMPLEMENTED ("search and remove a given Placement from current EDL");
       return false; // TODO
diff --git a/src/proc/mobject/session/sessionimpl.hpp b/src/proc/mobject/session/sessionimpl.hpp
index 658f5d56a..4e07f1a38 100644
--- a/src/proc/mobject/session/sessionimpl.hpp
+++ b/src/proc/mobject/session/sessionimpl.hpp
@@ -65,8 +65,8 @@ namespace mobject
         
       public:
         virtual bool isValid ();
-        virtual void add (PPla& placement);
-        virtual bool remove (PPla& placement);
+        virtual void add (PMO& placement);
+        virtual bool remove (PMO& placement);
         
         virtual EDL&  currEDL ();