Apple's LCD monitors are usually in the top two brands of overall quality/performance (the other currently being Dell's high-end). My monitor did not do it at all ever when it was brand new. After it aged a few years then I began to notice it, so I do think it is an age thing, though not sure why. If I have a high contrast image on the screen for awhile (time unknown, maybe 10-15 minutes?) and then move it, I can see the after affect... if I have a fairly solid wallpaper because it is much harder to detect on detailed surfaced. I've seen other monitors do this as well. Again it helps to have nice detailed imagery to lessen the effect. If you are looking at a web page which, say, has a black stripe on one side and the rest of the page is white, you can see the effect by reading the page for awhile and then moving your browser a little to the left or right, you can see the white column in the black area for a bit.