Crashing Delphi OpenGL program

I've got strange problem: I'm programming OGL in Delphi and after finishing program compiled from source, exception "Process ddhelp .... of module unknown" raises. If I want to run compiled exe-file, after finishing screen goes blue with typical Win error messages. It makes the same problem on WinME and Win2000, hardware is AMD Athlon 1.2GHz, nVidia MX 400. Could anyone give me a hint? I think I'm using original Windows - openGL32.dll and glu32.dll libraries (via downloaded unit opengl.pas) - isn't it necessary to use some nVidia library ...? Thaks very much for any reply

[Gavin]

Are you running it in debugger?

Yes, of course, but debugger says nothing and Delphi locks up - debugging process is still running and can't be stopped. This problem appears mostly with example program from www.opengl.cz, programming ('programovani') tutorial No.10. If you want, test it...

Thanx, David

[Gavin]

What I meant was that in windows 98 when I ran my delphi app through the debugger it would crash 75% of the time, if I ran it alone it was fine. It was somewhere in getting the dc that did it. Never figured why, it is now fine in 2000 though.