Hello. I got a new 21 inch iMac about two weeks ago, And i really like it but i have some questions. I noticed the sometimes after using it for a while, Some fog/condensation forms in that middle of the screen(behind the glass), Its hardly noticeable while using the computer, But after turning it off a large spot is clearly visible. After turning of the computer, The fog disappears in just about 10 or 15 minutes. I have only noticed this problem twice since i bought the iMac, And since the fog disappears quickly, I am not sure if i should be worried about this. Is this normal? Could it be because of the humidity/moisture in the air? The humidity in my city is at 90% right now, And there is a open window right behind the iMac. I'm really not sure if i should be worried about this problem.