Computer is one of the original Intel iMacs, 2.16GHz Core Duo processor, 2GB RAM, 1680x1050 20" screen, 256MB ATI Mobility Radeon X1600 graphics card. Recently, distorted artifacts have begun appearing on the screen while the graphics card is undergoing heavy use (e.g. games, DVD playback, other apps that use the card.) I have also had the screen freeze. This is happening in both OS X and Windows XP in boot camp, which confirms it to be a hardware issue. The iMac is covered by AppleCare, fortunately. Would Apple be able to repair the Mac, or would they simply replace it with a new one? If anybody has personal experience in dealing with faulty or replaced Macs, I'd appreciate their input here.