Did a search but I didn't quite find anything all that relevant. The weirdness just started happening a few minutes ago... shows up when I scroll up or down, but only sometimes. If it matters, I'm running 10.4.8 on a stock 2.0GHz MB C2D w/ 1GB RAM. Any preliminary suggestions? If it happens again, I'll bring it in to an Apple Store this weekend... But I'm curious if I should be worried or not.