Ok so first off, I dont think this is an image retention issue. I have a 15rmbp/2.6/16/512 from june 2012 via the refurb store (5 days ago). When I drag windows across the screen, I see what I would describe as a "cloud" effect in a few spots. Almost like the back of the front LCD cover is dirty or something. It cannot be seen when the window is still. Samsung screen :/ Any ideas what this could be? Its located roughly in the middle 3rd of the screen going horizontal in blotches. I'm wondering if its back light bands, but these are LED lit I thought.