I put an application together quickly using the NeHe base code, in VC 2005 Express. It was running fine, except this morning I’m getting no polygons drawn in Debug mode, while release mode works fine? I’ve not changed any project settings since I began.. It was working now it’s not. I know I’ve done something stupid, because an older debug .exe runs fine, but not sure what? I can trace the code, through my Draw function, GlClear works as it should, the primitives functions are being called.. (GL_LINES, etc) but nothing is showing.

Try doing a full rebuild and if nothing still shows up then try using glGetError at a few critical places.