Good morning. I am looking to purchase a used iMac, last year's model. It is a 20'' 2.66Ghz model, with nVidia 9400M graphics. In 2007 I had an awful experience buying a 20'' 2.0Ghz iMac. The computer was nice but the screen was washed out. The top of the screen was much darker than the bottom and colours were completely messed up. It was very ugly. I initially thought it was just a defect in my specific unit but when I had it replaced I noticed the same problem. So, does the early 2009 model of iMac have a good screen? Does the screen fade from top to bottom like in mid-2007 models? Thank you very much.