Using Full Page Heap to Find Heap Corruption
Compile the application in release mode, and run it under debugger after having enabled full page heap.
c:\debuggers>gflags -p /enable InDevelopmentApp.exe /full
c:\debuggers>start cdb -g -G InDevelopmentApp.exe
The heap instrumentation activated by gflags.exe is likely to put you very close to the place where the corruption has happened.