Blurs can be caused by "ghost signals". Ghost signals are most often caused by radio waves from multiple directions (just like a television antenna that gets ghosts from excessive radio waves). Check your video inputs to see if any other cable or a loose wire is connected to one of your video input jacks. An example: I disconnected my television (as a secondary monitor) from my VGA and S-Video cables but left the cables behind. The hanging VGA cable then created shadows(ghosts)on the text on my primary monitor. The television previously had grounded the wire to prevent picking up the extra signal, but once the cable was free, it acted like a mini antenna and created a ghost. The ghost disappears by either returning the television connection or removing the cable. There was nothing wrong with the computer or the cable itself.
Edited by kjsacramento, 01 November 2011 - 12:21 PM.