This is an interesting issue. I have the BFG Geforce FX 5900 Ultra and have had no problems like the ones described at all. I have played 15 games with it so far since I got it and no problems yet. I will be interested to see what Nvidia says tomorrow.
P4 3ghz 800 fsb.
Zalman 7000 alcu
1gb PC3200 Mushkin Dual Channel Kit
BFG Geforce FX 5900 Ultra 256mb
Vantec Stealth 520 Watt PSU
Sony X82 18.1 in. LCD Monitor