My iBook G4 randomly locks up. No kernel panic message. It is as if there is a pause button that is getting pushed on the screen and when it locks up if it is playing music it plays about 1 second then repeats. when I try the fix on http://www.coreyarnold.org/ibook/ it makes it take longer to lock up but it still locks up. I have tried bigger shims and that does not help. If I try to install Leopard on the iBook it doesn't even make it 25% before locking up. I would like to use this computer as a server if I could fix it.