Just purchased a brand new 24 inch iMac and after about an hour of use a yellowish tinted 'humidity bubble' has begun rising out of the bottom right of the screen. It seems as though the heat of the machine aggravated some water and is now coming up like a rising sun. Turning off the computer caused the bubble to shrink, but it was still visible. It is very annoying and cannot be ignored. Anyone else have a similar problem? How did you (how would you) go about fixing it? The Apple store is a bit of a drive and this is a real mood killer/inconvenience for the price of an Apple machine.