GeForce 6800GT Problem...HELP!

I recieved an XFX GeForce 6800GT videocard, and I believed the card was bad, as it produced corruption within BIOS\DOS\Windows\Windows startup on 3 different machines (2 Intel-based, 1 AMD-based). So, I sent in the card to XFX, and they issued me a "new" card (the card was obviously used, and was caked with dust). Anyway, I got the RMA'ed card in, and plugged it in to the PC, and the SAME GODDAMN thing happened as before . So, what the hell could be the problem? Is it possible that its my machine hates 6800's and kills them upon insertion into the AGP slot? I did notice that as soon as I plugged in the card and booted the machine, a puff of dust came out of the fan. It seems to me that the card was sitting on a shelf, uncovered, somewhere in the RMA depot, because the top of the card was CAKED with dust. Anyways, my PC specs are in my sig, and if anyone else with a similar machine has had problems with 6800's let me know. And yes, I did have the aux power connector plugged in, and my PSU is a 450w unit from Antec. Thanx in advance

<A HREF="http://goi.carnasaur.com/images/temp/corruption.png" target="_new">HERE</A> is what the corruption looks like from within Windows


P.S.

The BIOS version for my mobo I'm using is 1.4 official, and have also tried reverting to v1.3, to no effect, but I can't use earlier BIOS revs because they don't support 90nm CPU's

The card does seem to be all the way seated, and I am A+ Certified, so I should know

I am using NVIDIA's official 66.93 drivers

The clock speeds (for anyone that cares) for the card are the NVIDIA default 350 core\500 memory

I have also not overclocked anything (not yet)

Also, my other card, a BFG Asylum FX 5700 Ultra, works fine with no problems.

Athlon 64 3200+ (939, 90nm)
1GB Mushkin PC3200 DDR
MSI K8N Neo2 Platinum
NVIDIA GeForce 6800GT 256MB
Audigy 2 ZS
Western Digital WD2000JB
Western Digital WD1200JB
NEC ND-3500AG