Following is some text from one of my earlier posts here. Hopefully it will be of use to you or anyone else having similar problems. The main point is that certain discs with copy control (these are typically multi-session discs quite similar to Enhanced CDs) seem to be malicious, even to Macs.
On my PowerMac G4, I have ongoing quirks with the handling of audio CDs. However, in my case, what happens is that certain audio CDs simply won't mount; but I can still eject them normally and try again.
In the case of one particular copy controlled disc I unwittingly bought (absolutely no indication of copy control on the packaging, but only the tiny copy control logo on the disc itself), I can load it exactly one time and have it mount "properly" (i.e. with the audio CD session and the venomous malware session), eject it normally, but repeated attempts to mount the same disc are futile. The following is what I have to do every time things get squirrely, and it works every time:
Repair permissions by opening Terminal and running sudo diskutil repairPermissions /
Zap PRAM by restarting the computer while depressing the Option + Apple + P + R keys and waiting until I hear three or four startup chimes.
Once I've heard the third or fourth startup chime in the previous step, I immediately depress the Option + Apple + O + F keys until the computer boots into Open Firmware. Once there, I run the following commands:
reset-nvram
set-defaults
reset-all
As soon as I pass the last command above, I depress the Apple + S keys to boot into Single User Mode. Once there, I run the following command:
/sbin/fsck -fy
After the file system check and/or repair is finished, and the verification "The volume Macintosh HD appears to be OK" appears, I type reboot to restart the computer.
At this point, everything is reset so that audio CDs mount properly once again, at least until I work with one that breaks the normal working state of affairs.