The latest patch seems to have caused no end of graphical glitches with my game that were not there before.. but miffed as it makes some parts unplayable..
I hate to be a stickler with dusty old questions, but.. Have you cleaned the dust out of your computer and cleaned the fans blade's lately? That is a good video card you have there. Is your video card software up to date?
You do have a good point there...I often promise myself to dust the thing..but never really get around to doing it..so will give it a go tomorrow for sure :)