When sleeping, the Superdrive continously tries to eject a non-existent disc every few minutes. If there is a CD in the Superdrive, the computer stops trying to eject and works normally. As soon as I take the CD out and try to let the computer sleep, it keep waking up trying to eject the mystery CD. I have tried re-installing the OS. When I got the machine, I did import data and applications from another MacBook Pro. Could have this screwed up a setting? The drive actually works fine as I burnt a DVD the other day. Is this some sort of setting issue? Thank you for all your help.