This issue seems very widespread, and I also have the same issue on my 2.66GHz MBP. It is very hard to describe, but here are two pictures. http://picasaweb.google.com/hesunana/MacBookPro# And the official thread: http://discussions.apple.com/thread.jspa?messageID=10393710 It's noticeable in grey areas mostly, and in dark moving areas, the background of iPhoto can also exhibit a striping. Anyone else have this issue? Luke.