After a recent OSX update, I noticed that there are times the CD drives decide to stop functioning. The keyboard "eject" button no longer works, discs that are in them at the time disappear from the finder, and none of the workarounds work for me except to reboot and hope they come back.

However I've found something that does seem to work sometimes - DiskTracker's "batch scan disks" function will sometimes kick out a disappeared CD when it starts up. It worked on one Mac, but not on another. I am hoping the next revision of the OS will cure this miserable "feature!"