My 9 month old 1.67Ghz 17" PowerBook has a single red line running down the screen 1 pixel thick and about 200 pixels from the right edge of the screen. It just appeared yesterday. I have no idea what triggered it and how to fix it. The only thing that has changed recently is the OS update to 10.4.5, but I rebooted after that installed with no problems. The line just appeared whilst I was using the computer, I wasn't doing anything unusual or installing or reconfiguring. I've tried restarting (something I usually do very rarely), but that didn't make any difference. Does anyone else have this problem, or any idea how I can fix it?