[python-win32] "access violation" debugging advice?

[RayS]

I'm accessing a 3rd party ctypes cDLL function and getting 
WindowsError "access violation at 0xnnnn" at seemingly random time 
intervals; what tips does the group have for debugging? The DLL 
author is an MS C++ guy and not Python literate. The DLL appears to 
run without error with his MSVC apps. It almost seems CPU-load 
dependent, but I could be imagining that...
It is for data acquisition, and I seem to be forced to restart my app 
to get around the trapped error and restart (although I haven't tried 
un-setting the ctypes objects).

- Ray