THIS HAS GONE TOO FAR

[MetalMilitia]

Using an nforce board and an ATI graphics card will not cause a problem unless when you installed the nforce drivers you accidentally installed nvidia video drivers.

Or if you did not install the motherboard drivers at all you would be stuck in 'PCI' mode (not sure why its called that but its basically AGP 1x IIRC). Again that would make your system run like crap.

Its also entirely possible you issues are related to another part of your system. For example I used to have to use software audio in Battlefield: Vietnam because, dispite having a (then) decent sound card, EAX made the game run around 10FPS on low settings.

Powercolour aren't too shocking of a brand, they are certainly not the best but as far as I know they pretty much stick to the reference design.

Btw, which version of windows are you using for games ( I assume you are dual booting)? Did they fix the 64bit version so it does not suck yet?