I've had a recurring problem with cloudyness forming under the screen of my 24" Cinema Display. In the past I've taken it to the Apple Store and they've replaced the glass or LCD. The last time it was a nightmare because they chipped up the aluminum housing and they basically told me never to bring it back again unless there was a problem they could see in the full brightness which is the retail store and they gave me a new unit. Well the problem came back and this time I was on my own. I bought a couple of autobody dent removing suction cups from Amazon like I had seen the guys on ifixit.com use on a iMac and went to work. Removing the glass is pretty easy. Just lay the monitor down on it's back, apply both suction cups and pull straight up and it comes of with little resistance. After the glass was removed the problem was obvious. There was a tiny amount of dust around the edges of the LCD and apparently the very fine particles get past the foam seal and settle onto the back of the glass. Probably from some remodeling I'm doing on the other side of the house. I used glass cleaner and a microfiber cloth and cleaned the back of the glass and then sprayed the LCD and glass with a blast of compressed air from a can and put it back together. It's hard to see the smudges until the glass is in place and after a few more removal's and re-cleaning's I got it back together looking as good as new. The whole process was a bit nerve racking. Initially I was afraid the glass would come unstuck from the suction cups and fall and shatter but it's surprisingly light and that wasn't a issue. I posted this because I'm sure others have had this problem and when I was doing research I found posts saying it would void the warranty and "don't try it unless you have a clean room" and other things and I wanted everyone to know it's safe and you can get good results.