Check and make sure you don't have windows update KB2670838 installed.

Also, and I'm sure you don't, you don't have the anti epilepsy filter on do you?
I used to run Cliffs on a GTX285, on quite low settings, so it 'should' run on a 460, but it is in no way a great card for Cliffs.

ok, final verdict, the video card was not seated properly with the top screw in, for the card in the motherboard slot. Not sure why, but I can only use the bottom screw, which is fine, because it is the most important one for my video card. I ran, 3 flight sims, all ran without issues, then ran 2 3DBenchMark Tests, all ran great. Finally !! , been a long time with problems... ;)

all seems resolved...
yes, I can run on high settings.. it was the damned card that no longer seats properly with both screws btw, the video card is brand new, I just sent them back one I bought a couple years ago that had a problem, they sent me a new one still in wraps..