I just wanted to say - this is very odd. I booted into OS 9 tonight, in order to do some work in ProTools Free (man, I really wish they had a free version of 6 for OS X...), and I had the screen problem - but much worse! Whenever I clicked, or scrolled, the screen would jump around crazily. This happened in the Finder, and other applications. I went through my extensions, turned some obviously unneeded extensions off, and voila! the weird screen behavior went away on the next reboot. I am beginning to think I had classic running when I had the odd issues with Photoshop, as Photoshop does run in OS 9 as well (although I was working with it in OS X). John Pariseau PS - thanks for all the suggestions, will do the repair when I have some free time...