I have the same symptoms, and I removed RAM too. I suppose it is possible that all four modules in my G4/400 are bad. Would have been a recent development, though, as this was not happening under 10.3. Anyone have more ideas I can try? > Took out RAM modules one by one. Problem disappeared. > > A RAM module flaked out after 14 months. > > -- > > G4/400 10.4.3 Goes to sleep and wakes up to a spinning beach ball. Can't do > anything but a hard reboot. > > Zapped PRAM, reset NVRAM. What else could be going on? This didn't happen > under Panther.