[Rainy Day]

Briefly, the problem is this: Audio CDs inserted into a drive will not mount, and the system refuses to eject them. DVDs and data CDs mount/eject properly. This isn’t a hardware problem, nor a problem with the CDs themselves. Problem disappears when the Mac is booted off a system install DVD.

More details:

• The CDs don’t show up as icons in the Finder.
• Disk Utility doesn’t see them either, but offers the eject button on the drive. When pressed, Disk Utility hangs for about 30 seconds, them comes back with an error: ‘Eject Failed. The disk “PIONEER DVD-RW DVR-109” could not be unmounted.’
• The Terminal.app version of Disk Utility fails as well: drutil tray eject
• The keyboard eject button and the eject menu also fail.
• The only way to get the disc out of the drive is to reboot and use one of the various disk ejection techniques (e.g. holding down the mouse button).
• Discs inserted into an external FireWire drive behave the same way. The disc is locked in the drive by Mac OS X, and tray eject button on the drive is disabled. (Power cycling the drive, and hitting the eject button before Mac OS X scans the disc will eject it.)
• From Terminal.app, doing a ls /Volumes/ displays only the boot HD. df also fails to show audio CDs
• Logging out and into another account reproduces the problem (i.e. it isn’t a user preference file problem).
• When booted from a DVD, the problem goes away (external drive); returns when booted from HD. This suggests a problem with one of the Mac OS X system files.
• May be related to the fact that audio CDs usually mount with the generic name "Audio CD”
• fsck -f has been run

This problem occurred while ripping music CDs in iTunes. All of a sudden, the iMac refused to mount a music CD. After rebooting and freeing the CD from the drive, i discovered the iMac would no longer mount any other music CDs, including ones i had mounted only minutes before. So it isn’t a bad CD causing these symptoms. And since i have two drives, and the problem began occurring on both drives simultaneously, it’s not a drive hardware failure.

I believe Jay Chow, in this post, may be on the right track. But he doesn’t seem to know what’s causing the problem.

Has anybody solved this problem?

Please don’t suggest repairing permissions, resetting parameter RAM, and the usual “cure-alls.” Clearly this is related to a system file on the HD. The drive checks out fine.

Thanks in advance.

[CharlesS]

About the only thing I can think of right now is to open up the Console and see if anything telltale gets logged when you insert a disc. Other than that, I might suggest just reinstalling the OS.

[P]

Hard to tell, but my guess is that the extension for reading audio CD filesystems has become corrupted. I'd reinstall.

[Rainy Day]

Solved!

Thanks CharlesS & P for your suggestions.

I made a costly mistake in my troubleshooting: Logging out, then into another account reproduced the problem, but rebooting and logging into a different account — without logging into the tainted account† — didn’t. A subtle but important difference (as that does imply a user preference/data problem, and exonerates the system files).

The culprit ended up being the Gracenote Media Database file: ~/"Library/Preferences/CD Info.cidb”

Here’s my guess about what’s going on: When an audio CD is inserted, the currently active user’s Gracenote Media Database is consulted. If the database is corrupt, it can poison system RAM. From that point on, "all bets are off" for all users until the system is rebooted.

For reasons i don’t recall, i also replaced the file: ~/Library/Preferences/com.apple.iTunes.Gracenote.plist (I only mention this in case someone else having similar difficulties is reading this, and replacing the CD Info.cidb file alone doesn’t solve the problem.)

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† I think you have to log into the tainted account and try to load an audio CD before the problem actually arises.