Hi Hartmut/Volodya, I have been running v2 regression tests which build in debug mode by default. When the testwave_dll test runs, msvc-7.1 generates a debug assert somewhere in the dbgheap CRT memory allocation routines. However, if I copy the wave, program options and filesystem DLLs (rtti-off, runtime-link-static versions) into the testwave_dll directory, the problem went away. It is generally recomended to use the runtime-link-shared version of the CRT libraries if they are being used across an application and several DLLs. - Reece