I haven't noticed this before and wonder if I should be concerned. It seemed to start after I used Bootcamp, installed Windows 7, changed my mind and removed it again. Then reinstalled OSX (for other non-related issues). It seems to be a 'streaky' kind of 'marble' pattern during the boot process which goes away when it's all fired up. Any ideas? ---------- ...actually it's there all the time. Just need the right level of brightness to see it.