I have 27" iMac late 2011 thunderbolt model. This morning I have noticed what looks like lines and splodges on the top right hand side of screen, after doing quick search on here I've found it's a common issue. I've been straight on the phone to Apple care who have said to take into store on Monday morning for them to 'clean' the screen?!! It is just me?? As I'm thinking this will surely continue to happen after they have 'cleaned' the screen? Am I within rights to request a new machine or does this 'cleaning' of the screen really work? By the way no one in the house smokes, the Apple guy asked me this 5 times during the 12minute phone call!