graphical artifacts

I am having a weird issue with these red and blue artifacts on my screen in a repeating pattern. I think this is a hardware issue as I have formatted and reinstalled and I am still having the issue. I have zapped the pram, I even installed xp on a bootcamp partition to see if the problem persists. It does, though the pattern is different.

I was also surprised that when I took a screenshot of my desktop, the problem is visible there as well. This can be seen at http://imgur.com/wQSKC.png This issue does not happen on a secondary screen when I plug it in either, just on my primary mac display.

Any input on what could be causing this would be appreciated. I thought maybe it could be corrupted vram, but I am not sure. The closest apple store is quite a drive from here so I would like to prevent having to take it to the genius bar if at all possible.

Thank you very much for any insight.