My 24" early 2009 iMac has this problem that looks like a film has built up under my glass. I have always kept my rooms air conditioned with zero humidity, as well as never exposed it to smoke. It is still covered under Applecare, but I was wondering what they would do for me? Would they replace the LCD and glass or would they just opt to give me a whole new computer? Never had a problem with this computer except the 1 kernel panic from upgrading to 8gb, over the course of 2.5 years. Most reliable computer I have ever owned, and it is on 24/7 365.