I have a new PS3 and I've played Black Ops, Portal, Uncharted, etc. on it without a problem for 3 months. I borrowed my friends Modern Warfare 2 (which he got used at Gamestop) and it's been freezing up a lot on the loading screens on the campaign. It completely messed up and froze/got a disc unread error just now. My other games still work fine and the disc looks pretty good (except for a few scratches)...can a messed up disc mess my PS3 up? I don't care if this game doesn't work I just don't want it to mess up my PS3 for the other games. Note: The previous missions load fine...The beginning of the game and the current mission I'm on are the only two that have acted up.