I have been pulling my hair out over this trying to figure out why I randomly crash out on the ChoosePixelFormat API call.

Solution: It only happens if the first time I run my OpenGL app is after a frsh restart and I run it from the development environment (Borland's C/C++ or MSVC++). If I only run the EXE first time out, no problems at all.

go figure. At least I know how to stop this madness.