I know there have been plenty of threads about this, but lately this issue has started to really bug me. Sometimes (more often than not) my iPhone 4 will have very, very faint horizontal lines across the screen. They're really only noticeable on a grey or blue background (Facebook icon, keyboard background etc.) but they really detract from the picture quality. I don't think this is a hardware failure for two reasons: They aren't always there, and I don't think I've always had this issue. I've only dropped my phone once, and that was after I started noticing these lines. You can test for this issue by opening the attached picture. The upper and lower bars will flicker. (The ones that say the picture number, delete etc.) Anyone else? And is there a fix?