Accipiter22,
I had similar experiance with my 6600GT SLI. Everything started to look and run great when I updated my nForce drivers and my video drivers.
Check out
http://www.3dchipset.com
They have alot of altered and beta drivers for ATI and nVidia for chipset and video.
I did notice that nVidia finally updated their website as well but this site may help in the future. I got the SLI profiler from 3dchipset when it wasnt available from nVidia.
I used to use
www.reactorcritical.com alot a few years back for the same but they closed shop. Glad I found another source.
I hate digging through ftp sites I liike to let other do it and collect it for me.
I'm lazy!
EDIT: and for you ATI only guys, I have an x800 Pro in my 2nd machine. It is a great card, awesome!! But, so is nVidia. Other than the nVidia GPU being more advanced with sharper Pixel Shader 3.0 (who reallyy cares!) , both cards look awesome (ATI and New! nVidia cards)
I thought that the FX5950 I got 2 years back looked washed out as far as color and wasn't as clear and shard. Where the ATI colors looked much more vibrant and the speed differance was noticable in my 9700 Pro.
But don't get stuck in a paradyme, keep an open mind and don't be a fanboy of any Vendor. Stay objective. It always ends up flip flopping who's on top.