I am running an ATI Radeon 64Mb DDR ViVo card on a Windows 2000 SP2 machine with a Asus CUSL2-M board with 416Mb of RAM. I have the latest drivers from ATI.
My problem is: When playing Counterstrike, if I set the resolution higher than 640x480, the screen goes to that resolution (e.g. 800x600) but CS only shows up at 640x480.
Help PLEASE!
I think Radeon has problem with CS and OpenGL but D3D works fine. Maybe was it the other way around… 
Doh. If I set it to 800x600 OpenGL, sometimes it works and sometimes it doesn’t. If I get the “Loading…” screen when I join a game, then it’ll work, otherwise, it doesn’t. Anything higher than 800x600 doesn’t work but usually hitting ESC and joining a few times, it finally works.
This bites. I didn’t spend $180 for a video card so I can’t play at high res… 
Well, I had the same problem w/ my Voodoo 3 3000 in Quake 3. I fixed it by getting different drivers. So maybe try getting some older or third-party drivers(if there are any) and see if they work.