Doom 3, getting horrible framerates

This is perplexing. I've got an evga 7900GT KO, a core 2 e6600, 2 gigs of corsair XMS2, and for some reason I'm getting like 15 or 20 FPS. According to numerous tests and benchmarks I've read, I should be able to destroy Doom 3 at full settings w/ this card, but for some reason I'm not. I had the same problem with the Quake 4 demo. Is there some reason that the Doom 3 engine hates me? I'm getting good framerates in my other games, I can get 30 FPS in FEAR at max settings...so why isn't this working? Anyone know?

When I play doom 3, I get nothing but whiteness...

Quake 4 same way.

I hear ya