By Valefor.Slipispsycho 2010-05-14 22:14:47
My only guess would be that some how the new CPU has either messed with DirectX, or your video drivers. (on a software level)
Google around to see if your new CPU has any known issues (and possibly a patch) with either, or at the very least, uninstall both, and reinstall with latest DirectX, you might have to tinker with which version of video drivers work right, start with what worked before, then go back a couple of updates, if nothing, then go to the most recent.
I know it sounds weird, but hardware and software have a really delicate balance, and the slightest thing can throw them out of whack.
Also if your video card uses 2 6-pin connectors, make sure they're both in securely.. Most components these days are designed to shut off/reduce load in lieu of causing damage, and one of those pins is what powers the fan, it may recognize this problem and refuse any load, hence the '*** off I'm not playing that game'