Lately it's been revealed that starcraft 2 has been melting a lot of video cards. If you start experiencing random choppiness and not from the internet then close the game ASAP. Blizzard should have a more official fix in their next patch. http://multiplayerblog.mtv.com/2010/07/29/beware-starcraft-2-melting-video-cards-do-this-or-else/
Yeah, seems a lot of people are getting their video cards toasted. I am still inclined to believe this is nVidia's fault, because this issue appeared AFTER nvidia released drivers during beta.
