performance/quality issue w/ 6600GT

[DeathCrush]

greetings all... ok, this is driving me nuts, i've been searching for a while now and i can't find anything so any help here would be gladly appreciated.

i just bought a 6600GT and everything works totally fine under windows, but when i use it under Linux (i'm using Doom3 as a test) the quality is less that i expected.

my old card was a Radeon 9600XT and i had the option of a "performance/quality" slider to mess around with under windows. when the slider was on the performance side the image would be fuzzy/pixely and when the slider was on the quality side it was nice and crisp. right now under Linux the game looks like it would if that slider was on the performance side (all fuzzy).

now i KNOW that it's not an option in the game, everything is set to the max (and i've even tried setting everything down really low as well) the only thing i can think of is that there is some option that i'm somehow missing.

sorry to be bothering all of you with a seemingly newbie question, but this is driving me nuts at this point. thanks for any help, here are the specs for further assistance as well:
6600GT
Linux 2.6.10 kernel
Slackware 10.0
newest nVidia drivers (released on march 11th, don't remember the exact version number)