OK, a few months ago, I upgraded my iBook G4 from a CD-ROM drive to a Combo Drive. However, I lost the sleep magnet somewhere along the road. (the magnet that activates the reed switch that puts the computer to sleep when closed) Does anyone know if the magnet on one of the screws under the keyboard would work to replace it? And also, what is the magnet under the keyboard even for? And also, if it won't work as a replacement, where could I buy a new magnet?