I have this strange problem on both of my computer. I own an intel based MacBook Pro and a G4 iBook. Both have a mighty mouse and have up to date version of Os X. I have an Epson 2200 printer that I use on both computers ( the drivers are installed accordingly on both computers). For a reason I don't know I'm experiencing a strange behavior on both computers. When my printer is connected (it's always connected via Firewire) and when my mighty mouse is also connected everything on the desktop moves away like when I use F11 of Expose, it comes back in place and then it starts again at a quite fast speed. It's like if I was pressing F11 on and off at a fast speed. Sometimes it stops by itself but most of the time I have to press F11 to get everything back to normal and if I do it or If I try to use the mouse, it goes back to that strange behavior. The corners are not programmed to clear the screen so it's not that. As soon as I unplug, the printer ( or I turn it off) or the mouse everything is back to normal. I have the same exact problem on my brand new Mac book Pro.
G5,DP, 1,5Gb, Macbook Pro, iBook G4, Mac OS X (10.4.7)