i have a gtx 560 ti twin froz II and i didn t have any problems with this card.i play with a 24 inches screen in a 1920x1200 resolution (with all option in maximum i have only a few stuters and a bit more over london).if i were you i woud try to desinstall the game.i don t think it s come from a driver because there are two and i tried both without any problems.i hope it will help you for your further investigations.
