I have a 2009 iMac. While it boots up with the white screen and Apple logo, you can see a real dirty shadow with hard outline on the right of the screen. It has never really bothered me. I rarely notice it when I am using my iMac, except for when dealing with certain color screens. On Blue screens, I notice it more than anything else. Anyway... I have Apple Care that runs out in November. If I took my iMac to the Apple Store at this point complaining about this problem will they simply replace the screen or does the entire unit have to be replaced?