They seem to appear on things that I'm working on and they stay until I switch windows. There's one now, sitting right next to the text box that I'm typing this in. When I scroll the window up and down, it breaks into rectangles and other rectangles appear and disappear. When I stop scrolling and start typing, they freeze and stay where they were. These are not boxes around text from Voice Over. They are solid and random.... and they all just disappeared again. But they'll be back soon. I'm on a g5 power pc. I've changed the hard drive and they're still here. Little help? Thanks!