driver problem ?

[Sumoquirkey]

Im still having problems with my graphics card,gtx 480..causing my pc to go into power save mode,and usually resetting,which then takes a few attempts to log back into windows 7,i only play planetside 2 ,settings on medium.What i dont get is i can play ps2 all day fine then go to play it next day and it will keep locking up or resetting after i get the 'going to power save mode' message ,even just browsing the net after boot up can cause resets,even though nothing has changed on my pc !.my only thought is down do driver problem ,currently using 310.90 ,but i have only ever used the nvidia updater when upgrading drivers,so unless a problem has come out of using that im stuck on ideas.
Any ideas apreciated or more info needed

cheers q