always had distorted graphics in Unreal Tournament OpenGL, nothing seemed to fix that. Downgrading to the first hacked Detonator drivers was as useless as upgrading to nVidia´s newest stuff. Strange thing was, using Direct3D seemed do solve the problem but tradeoff was that Microsoft´s API is ALOT slower than OpenGL. So I played a little with UT´s settings in the "UnrealTournament.ini" file and came up with the following settings:
 
Translucency=True
VolumetricLighting=True
ShinySurfaces=True
Coronas=True
HighDetailActors=True
DetailTextures=True
DescFlags=9
Description=NVIDIA GeForce DDR
Use32BitTextures=True
UsePrecache=True
UseMipmapping=True
UseTrilinear=True
UseMultitexture=True
UseTripleBuffering=True
Use32BitTextures=True
UsePageFlipping=True
UsePalettes=True
UseFullscreen=True
UseGammaCorrection=True
Use3dfx=False
 
if everything works correctly with this posting, you should be able to copy & paste these settings directly into the "[OpenGLDrv.OpenGLRenderDevice]" subsection of your "UnrealTournament.ini" file (of course without the " ). Don´t forget to make a backup of it before tampering with it! After 8 hours of continuous UT gambling I have to say these settings work like a charm.
 
I hope this helps other people as much as it helped me