I'm running 10.4.11 on a Powerbook G4 (1ghz) with a gig of RAM. No matter what application I'm running or what I am doing (scrolling, typing, viewing), every minute or two the Finder jumps to the front and whatever I'm doing stops. The app remains open in the background and I have to click on the app window to reenter from the finder. I've never heard of this and have been using Macs forever. Any advice?