The bus is the medium that all of the cpu connects to so .. was my suggestion of overloading .. /poor connection. Since you have a laptop I'm reasonably certain the bus speed is much slower than the desktop G4's & 5's. Something ain't coping ... I saw that issue on some of the older SCSI HDD's once in a while. How fast is your HDD. My guess is it's only a about 5400 rpm. Most nowadays use 7200 rpm. But just some thoughts b/c I'm not sure what's caused it. I do know a lot of the early G4 laptops had some issues. Frustratingly sometimes ... but that's what I saw of other people's ... I've never had a G4 laptop.