Nvidia GTS 250 overheating under NO load?

So here's my problem, i haven't seen this same thing so i figured i would ask. I have an nvidia GTS 250 all has been well for two years. I came in from dinner yesterday and noticed that my gpu fan, which is set to auto, was cranking at about 100% which is weird because there was nothing going on the computer. I pulled up EVGA precision and it was at about 83 degrees. normally i am around high 50's or so.it wouldn't come down no matter what. i thought it might be the new video drivers recently installed, so i tried the next beta and even rolled back and still the same thing. before i went to bed i tried watching Netflix. after about 5 minutes or so everything would stutter. as soon as i would touch my mouse it went back to fine. i shut it down and came home from work today. fired it up and temps seemed ok. played some small games and internet stuff, temps are all ok. walked away for a few and came back, temps were back to the 80's? as soon as i touched the mouse again, the temps started to fall a little. i figure it's the card so i take it out and set up a rma with EVGA. I put in an older 9800GT and it's doing the same thing. as long as i'm doing something on the computer all is well, but as soon as i stop the temp just shoots right up. anyone seen or had something like this happen? any ideas?

ps sorry for horrible grammar and spelling

Virus? Sounds strange, but given the advanced nature of modern viruses, such as Stuxnet, it would not surprise me if there are viruses that can affect computer fans. On the other hand does your motherboard have some sort of "smart graphics fan" feature in the BIOS? Usually this sort of feature is reserved purely for system fans, but it is possible that there is such a feature on your motherboard. If you find a "smart fan" feature, try disabling it - and then hopefully things will improve.

Thanks for the response. i'm running a virus scan now, but i can't imagine that i would get one. especially when nothing was going on, and nothing else with the computer has changed. I'll double check the bios but again nothing has been changed in the settings.

could it be something with the power supply?

you didnt say whether you opened your task manager and checked to see what was running in the backround.
i would look there first..