Driver Trouble

Heya, i never used to have this problem and i dont know when i began happening. Im running an AMD Athlon 1.2 with 256meg SDram and a Geforce 2 GTS 32meg (Asus 7700 deluxe) Im also running WINDOWS 2000 professional.

I recently installed UNREAL TOURNAMENT but noticed that the graphics were terrible. When attempting to run the game in Direct3d it is jerky and the graphics are terrible, even while running at a resolution of 640x480 with 16bit colors. Yet the game runs perfectly (although dark, and the brightness doesnt change) in OpenGL, i can even run at 1024x768+. At this time i had ASUS's most recent drivers for my video card and directX 8.0 installed.

I tried changing the drivers around, using nvidia's drivers and directX8.1 and using the UT 436 patch, but still no luck. It's strange seeing how I should have far better performance using Direct3d than OpenGL. Im also getting very poor framerates in VideoCard benchmarking programs (5.6fps in particle fury)..

Another thing is that Rogue Spear runs fine on my machine and im able to run at resolutions of 1280x1024+........

Does anyone have any idea what could possibly be going wrong.