Hi, I have an C++ application that uses the Oracle OCI libraries(oci.dll), which itself has references to msvcr71.dll. I compiled the application with gcc 3.4.2 under MinGW and for runtime usage I downloaded/installed the desired msvcr71.dll. From "installed.ini": [components] runtime=mingw-runtime-3.11.tar.gz w32api=w32api-3.8.tar.gz ... The program crashed at exit with the following error message in a dialog window: Microsoft Visual C++ Runtime Library Runtime Error ! abnormal program termination Because I want debug the error I installed gdb 5.2.1. When I run the program in gdb I get the following message: Program received signal SIGTRAP. Trace/breakpoint trap. ... warning: HEAP[...] warning: Invalid Address specified to RtlFreeHeap(230000, 246950) In the backtrace I see that it happens in OCIInitialize. So I suppose it has something to do with the oci.dll and msvcr71.dll. But I'm able to run the application outside the debugger and beside the crash at exit it is working. How can I debug my application ? My OS is Windows2000. Thomas -- http://www.randspringer.de