Video freaks out when windows are moved around on the screen
Hi All! Another wacky 15" PowerBook question: I've got a machine that works 100%, except when you move a window or an application, even slightly, the image within that window freaks out. Please see the attached picture for an idea of what this looks like. It's as if the computer doesn't have the ability to refresh the image fast enough inside the window, and so it leaves it garbled. If you close it, and then open it again, it's normal again until you move it. If you move an icon, it's fine -- it's only when you move a larger app or window. It does this very consistently, and there is no additional screen-garbling other than this issue.
I've done all the resets. I've connected an external display, and the defects show on the display, which logically tells me the board is probably at fault. I've swapped the RAM, tested the slots, and tried both Tiger and Leopard on different hard drives, and the problem persists. I've tried different screen resolutions.
I would typically just write this off as a bad board and a video issue, but I'm fascinated that the problem is so reliable and so specific, whereas most video issues are random and all-encompassing. And like I said, the machine works perfectly as long as you don't move stuff around.