I have a 20" ACD (the G4 style) and last night it suddenly started acting up. It's hard to describe, but there is a light blue tint covering parts of the screen and it jumps around. I tried to take a screenshot, but it doesn't show it. Any idea what is wrong or what steps I can take to diagnose it? It does not happen on my pb's screen, which is what it is used with. Since the screenshot didn't show it, I should add that it is very noticeable and makes it hard to even use the screen. The blue tint flickers and flares and covers most of the screen at any given time.