the fan profile might be set at so low voltage at low temperatures that the fan just doesn't start right away, thou after the kickstart it's still able to maintain the speed... If you leave it be and just idle on the desktop does it eventually start on its own once the temps have risen a little? use GPU-Z to monitor temps and what not..
what kind of temps do you get when you are in a game? Also, I want to circle back to Kari's questions because its a good one when you idle on your desktop or when you start something does your fan start to kick up?