Sorry, but downloading the latest drivers don't work either: I recently bought a NVIDIA GTX470 ("Point of View") and I'm getting the same weirdness gav24088 gets. I downloaded both the display drivers recommended by my linux distribution (Fedora 12) as the latest from nvidia. After that, I tried other linux distro's, older and newer ones (Knoppix 5, 6, Fedora 13), still no difference...
I've opened a thread here about my problem: http://www.tomshardware.co.uk/forum/295807-15-weird-nvidia-gtx470-randomly-crashes-system-black-screen-corruption
There's also someone else suffering of the ~same problem: http://www.tomshardware.co.uk/forum/295976-15-problem-under-powered
The suspicious thing is that I've got also a ASUS mobo (P7P55D-E)... But since I use Linux, I didn't approach the "Asus Smartdoctor", so don't expect the problem lays there.