Gtx 560 ti Overheating way to fast?

I went out and bought a GTX 560 ti graphics card. installed it into my computer. its been roughly 3-4 months now and i havnt had ANY problems with it. ( Minus the headache of getting it installed at first) And now for absolutely no reason it tends to overheat in a matter of minutes or even seconds. games i used to be able to run for HOURS like Battleforge, Team fortress 2, Black prophecy now all crash my card within a matter of 1-2 minutes. i havnt changed a single thing. i keep the room temp down. i have the case off the side of my computer. iv already took the card out and throughly cleaned it. i put my hand on the bottom of it. ran tf2 within a minute it was super super warm. both of the fans on the top of it are working. they have plenty of space between them and the psu. a good 2-3 inches more than enough. but none of this seems to work. iv tried using google to find out an answer but i cant seem to find any. so here i am on yahoo answers >.< Any help would be appreciated