I am running a gigabyte 7970 ghz and i have this glitching and lines happening at random times. It sometimes happens when i bump the desk and if bumped again it stops. i already swapped pci slots and got the same thing. i swapped PSU cables from the hardwired ones to the removeable ones. I have no idea what is causing it. i have only had it a couple of months. it glitches periodicity.