I have a 17" powerbook that keeps ejecting cd/dvd's. Tries to read them then ejects them after about 10 seconds. The dvd drive itself is fine. Hardware tests indicate it is working fine and have had it checked by an apple specialist and he says it is fine. It must be software issues. Ideally I would do a software restore but cannot put the discs in. What can I do about this? It must be a fairly simple solution. Any help greatly appreciated.