I have not seen any posts comparing these two symptoms together, but I am wonding if both exist on the same screens, or if they are infact seperate issues. I returned a 27" iMac i7 because it had both slight yellowing and terrible backlight bleeding. I have seen multiple machines first hand (3 Core 2 Duos week 41s) at different stores (Apple and Best Buy) that had no yellowing and no backlight bleeding. I won't get into how to check for yellowing, you can read about that issue here: http://forums.macrumors.com/showthread.php?t=824940 But to check for backlight bleeding is both easy and impossible not to see if you have it. To check for backlight bleeding, a quick way is to bring up a site like http://www.blackle.com/ or any other black background, and check for an inconsistent white glow on the edges of your screen. I had serious backlight bleeding in the lower corners of my screen, which happens to be where the yellowing was happening. I don't know if they are related, but hopefully we can determine if there is any correlation here. I did order a second machine, because I know Apple knows how to make a 27" iMac with a perfect screen (as advertised), since I have seen 3 of them in the wild. Hopefully they will be back to the quality that they had is their early production units very soon.