Hi. I have a power book G4 and my hard drive continuously stops and starts spinning again. I've checked the option to "go sleep when possible" at the energy settings, but I don't understand why it keeps waking up even when the computer is idle (for example, when I am reading something). Any clues on this matter? Btw, I know about the disk because of the sound it makes whenever it stops or starts over. Thanks a lot. Lásaro.