VT7 board

Hi

I just purchased a Gainward 6800 GT Golden Sample, the card runs as
promised. I have noticed one problem though, when exiting DOOM3 or COD my
machine freezes.

I did not have this problem with the ATI 9600 that I replaced with the
Gainward. Has anyone else seen a problem like this?

I do not have fast write enabled

PC Spec's

Abit VT7 VIA PT880 chipset
P4 GHz 800fsb HT processor
1 gig DDR 400 memory (4 - 256 chips)
350 power supply
Gainward 6800 GT 256 meg Golden Sample

Thanks in advance for any help

Roland