diff --git a/src/lib/diagnostic-context.hpp b/src/lib/diagnostic-context.hpp
index 221f59fad..5d3167fee 100644
--- a/src/lib/diagnostic-context.hpp
+++ b/src/lib/diagnostic-context.hpp
@@ -124,6 +124,10 @@ namespace lib {
        *         on the thread-local diagnostic stack. Might
        *         be empty. Values start with frame next to
        *         the current scope and end with outermost.
+       * @warning can be inefficient on very large stacks
+       * @todo benchmark and improve the data structure
+       *       used for the snapshot. Vector is not
+       *       an optimal choice here.
        */
       static ValSequence
       extractStack()
diff --git a/tests/40components.tests b/tests/40components.tests
index b1a93d5d1..4f60cf263 100644
--- a/tests/40components.tests
+++ b/tests/40components.tests
@@ -679,7 +679,7 @@ return: 0
 END
 
 
-TEST "Thread-local diagnostic context" DiagrnsticContext_test  <<END
+TEST "Thread-local diagnostic context" DiagnosticContext_test  <<END
 return: 0
 END
 
diff --git a/tests/lib/diagnostic-context-test.cpp b/tests/lib/diagnostic-context-test.cpp
index 008c37af5..ba1183510 100644
--- a/tests/lib/diagnostic-context-test.cpp
+++ b/tests/lib/diagnostic-context-test.cpp
@@ -1,5 +1,5 @@
 /*
-  DiagrnsticContext(Test)  -  verify thread local stack for collecting diagnostics 
+  DiagnosticContext(Test)  -  verify thread local stack for collecting diagnostics 
 
   Copyright (C)         Lumiera.org
     2011,               Hermann Vosseler <Ichthyostega@web.de>
@@ -39,8 +39,9 @@ namespace test{
   
   namespace { // private test setup...
     
+                             /* WARNING: memory hungry */
     const uint NUM_THREADS = 40;
-    const uint MAX_RAND    = 1000*1000;
+    const uint MAX_RAND    = 100*1000;
     
     inline bool
     isOdd (uint val)
@@ -80,7 +81,7 @@ namespace test{
    * @see lib::ThreadLocal
    * @see backend::Thread
    */
-  class DiagrnsticContext_test : public Test
+  class DiagnosticContext_test : public Test
     {
       
       virtual void
@@ -147,6 +148,9 @@ namespace test{
        * take a snapshot of the full ContextStack and then unwind.
        * Thus the captured numbers must from a decreasing sequence
        * of odd values.
+       * @warning this test case causes memory pressure.
+       *          The reason seems to be the frequent re-allocations
+       *          of the vector used to take the snapshots 
        */
       void
       verify_heavilyParallelUsage()
@@ -206,7 +210,7 @@ namespace test{
   
   
   /** Register this test class... */
-  LAUNCHER (DiagrnsticContext_test, "function common");
+  LAUNCHER (DiagnosticContext_test, "function common");