Never seen anything like it!

I've been using my iBook in the same location, with the same external trackball for over two years now.

This morning, I discovered that the display appearance was slightly "fuzzy," but weirder still, the display moves when I move the trackball or use the trackpad on the iBook!
It just jiggles a bit up, down, or sideways, and stays put until I next move the mouse, so it's totally usable right now, but weird.

Any ideas?