8800 GTX BSOD problem... any ideas?

Whats up

I've just built a new gaming system, much to my dismay, I can't game on it.
What it has:
Athlon 64 x2 5200+
Asus M2N32-SLI Deluxe Wireless edition
2gig Corsair XMS2 DDR2 800 (set in BIOS to recommended settings of 5-5-5-12, 2T, 1.9V)
320 gig Seagate SATA
EVGA 8800 GTX SC
Antec Truepower Trio 550W
Thermaltake Armor Series case with 2 120mm/2 90mm case fans
Vista Home Premium

So, everything with this system works great, right up until the video card is under any kind of load. I started out by kickin on WoW, max settings at 1600x1200, immediately noticed artifacting/clipping graphics. Not long and I had my first BSOD, referencing nvldmkm.sys (something like that, I have it written down somewhere, I know there's another m or d or something in there). I rebooted, and for the hell of it, turned WoW all the way down, to where it looked like I was playing doom on a 486. It actually ran stable for a good hour, and then blue screen'd with the same error.

I've tried all the different driver's nvidia has been releasing, I've ran memory tests and my 2 gigs are fine, installed XP and XP driver's and still had BSOD under load, although while XP was installed, I did manage to get a full Aquamark and 3dmark05 completed.

I'm back to Vista again and with the new WHQL drivers. Running the Cascade Directx10 demo, computer blue screens after anywhere from 5 seconds to a few minutes into the demo.

Has anyone had a problem like this or does anyone have any ideas?

yes it sounds like the card is bad