Nvidia Cards on Vista x64 (RTM)

I've just build myself a new high-end PC including a 7900GTO gfx card. I
dabbled with XP Pro but had a few graphical problems so I thought I'd
install Vista (rtm) instead, whcih I did. At first, everything looked OK,
but when I started using more demanding applications (i.e. 3D games) I
encountered some artifacting and distortion. Particularly in Battlefield 2,
Civililzation IV, and Oblivion, but also periodically in Vista itself. The
problems in-game were consistent at least, and the problems wihin Vista
itself were intermittant, occasionally resulting in a STOP error.

I tried a (borrowed) 7300GS card (which doesnt need auxiliary power) and it
had the same problems in-game, which suggests the problems were not to do
with the original 7900GTO not the PSU. Obviously the most likely candidates
were Vista and/or Nvidia's drivers.

I tried a few drivers from various sources but could only get a couple to
install and neither were any better than the default Vista drivers.

I decided to by a high-end ATI card for comparison, and I installed an
X1950Pro last night. Using only the default Vista drivers, I suddenly found
everything worked great. So it seems the nvidia drivers might be the problem
after all.

I was just wondering if anyone had success or similar problems with high-end
Nvidia cards in Vista (RTM). I've seen nothing on the NVidia site to
indicate when final versions of the drivers will be realised; I'd like to
keep the 7900GTO if I could but obviously it's not usable at the moment.

CJM