Toribash
When in doubt, reinstall. If the problem persists, I'd suggest updating your graphics drivers if they aren't already up to date.
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I've had a problem like this before but it was with an old CRT monitor, and the problem was a lose wire in the VGA connector. Otherwise, this seems like a pretty strange issue.
Last edited by Sparta; Nov 12, 2015 at 11:44 PM. Reason: <24 hour edit/bump
[20:07] <@SpartaCraft> This is the sexiest potato I've ever made.