Are the problem drives Apple or aftermarket, and are they in good shape? A dodgy drive can take 15 minutes to default out in the system and re-open the door, quite a pain in the sitting part, and not a system fault, particularly.
A flaky LG DVD-RW screwed me up quite a bit, would lock up even my external USB drives. Replaced it, everything works fine now, but the system now checks for a disk periodically, unlike before.... Peter
