This one has me stumped, I'm hoping someone has come across this before and found a solution... I just got an external display to use with my Powerbook, and it works great, I've very happy with it except for one issue: I can run it on dual-display setup and it works exactly like it should. But when I try to use it in closed-lid mode, the image on the external display 'jitters' back and forth, just one pixel, right and left. Its almost like the display is trying to auto-adjust constantly. I'm running it on the same resolution and all settings are the same. I don't think the problem is when the monitor because it only does it when the Powerbook is trying to use it only and not its built-in display. Occasionally it will work properly. I thought it might be heat-related, but it does it right from the beginning, so its not like heat is being built up from having the lid closed. I've tried turning the monitor off and back on again and that doesn't help when I'm having the problem. Like I said, I don't even know anything else to try. Anybody got any ideas?