Every once in a while a CD would not mount on the desktop but would be visable by disk utility. It would happen with original CD's, Data CD's, Music CD's and burned CD's.
I would try restarting etc... nothing would get it to show up! I tried restoring the permissions, nothing. Disk utility was not finding any problems either.
Finally out of desperation I decided to log in as a fake user and see if that user could see the disc... and it could!
I never had this problem -- until very recently. Some update has messed up drive mounting.
I wonder if this plays a role in the problems many have with mounting firewire drives.
This tip does work, but not if one uses fast user switching to switch to an already logged in user. It's only on initial login that the drive can be seen, and ejected or mounted!