Currently Being ModeratedNov 10, 2012 4:22 AM (in response to Kalebe)
Maybe your video card is going bad. Run the hardware test on the 'extra software disc' that came with you Mac.
Currently Being ModeratedNov 12, 2012 3:24 PM (in response to Kalebe)
Shut down the machine, open up the side, pull out your card and blow off the dust build up. While the card is out of the box, do a little vaccuming/ cleaning of the insides then reset the card back in the slot and reboot.
If that doesn't work, either the power supply to the card is not working or the card is beginning to fail.