Okay, sounds like it may be hardware afterall.. haha.
Dug around some more on the Dell forums and a number of people had their cards replaced and everything runs fine now. One person also says to he got it fixed by flashing the mobo with an update, but got the card replaced anyways.
As for...
I really want to try to avoid that, unless i'm almost sure it's a hardware problem. Last time I called them it was 2hr lesson in computer 101. He had me reboot and try again.
Hoping for someone with similar experience and a fix.
I'm actually getting the EXACT same problem with FEAR you are. I have a Dimension 9200 and a 7900GS setup.
Have you had any luck to your problem?
I only have 2 games, the other being Company of Heroes, and that one runs fine.