I have also some problems with my external display (hp lp2475w) When i connect my late 2008 mbp to this screen i'm seeing flickering white/green pixels all over the screen. I've contacted Apple but they had no solution for this problem. I have no problem when i connect my early 2008 mbp to the screen, so i think it's really a problem with the mini display port or the minidisplay port to dvi adapter. Are there other people having the same problem? Maybe there is a solution for this?