I have a problem with my video card (gforce 7900GS). After about 5 to 10 minutes of idle my screen will go black and the fan on the video card will increase in speed. It dose not come back on until i flip the switch on the back of the power supply off and restart the computer. I checked the card temp with Ntune and it is at 50c right before it goes out. This card is about 5 months old and i have never had a problem before. Also, i am not overclocking and all drivers and software are up to date. Has anyone heard of an issue such as this?