What the hell?

Okay, whenever I open ZdoomGL it just flashes strange colors on the title screen and I can't do anything. I'm using a Radeon 9600 pro videocard. How do I fix this?

does it do it both in windowed mode and fullscreen mode? Make a shortcut to zdoomgl.exe and add "+fullscreen 0" to the target line to run in windowed mode (without the quotes).

Hmmm it doesn't do it when it's not in fullscreen. It still does it fullscreen though.

hmm, what happens if you set gl_vid_refresh to 60 (run with "+gl_vid_refresh 60" on the command line)?

God dammit this is just really fucking annoying. It didn't work.

Try changing the resolution or something. And are you sure you changed gl_vid_refresh to 60? (look in the zdoom.ini file).