Mounting a CD on my test box doesn't lock the IDE CD drive bay... I can still eject the CD using the eject button on the front of the drive and remove the CD and then have a lot of fun with mount still believing the CD is in. I think that the drive should be locked when the media is mounted.
Are you running magicdev? Sounds like a known problem with that.
Well magicdev is installed but GNOME/X isn't running at the moment? Isn't magicdev just automounting/unmounting CDs when GNOME is running?
Okay, made a fresh start of the system and this time it works as expected (CD drive is locked when mounted). Appearantly, magicdev is left running somehow even after shutting down GNOME/X. I couldn't find the magicdev bug you're referring to, though, so I couldn't mark this as a duplicate myself.
*** This bug has been marked as a duplicate of 13628 ***