So this started awhile back but it seems to be getting worse. When I have light shades on my monitor (white, light grey etc.) there are tons of little ripples that fluctuate. They often stick to the top and bottom of the monitor, but sometimes they cover the whole thing. I haven't introduced any new electronics to the set up (magnets/speakers and the like) so I'm confident that's not it. Also, if i thump my computer agianst the desk they'll go away temporarily. What's going on here?