Latest working kernel version: 2.6.20-16
Earliest failing kernel version: 2.6.24-12
Distribution: Ubuntu-8.04_ppc
Hardware Environment: ibook G4
Software Environment:
Problem Description: when I tasted to mount a audio cdrom, mount failed, only for audio cdrom; other cdrom works correttly.

Steps to reproduce: 

pietro@trip:~$ mount /media/cdrom0
mount: block device /dev/hdc is write-protected, mounting read-only
mount: wrong fs type, bad option, bad superblock on /dev/hdc,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

pietro@trip:~$ dmesg | tail
[ 1388.428934] ide: failed opcode was: unknown
[ 1388.429343] hdc: error code: 0x70  sense_key: 0x05  asc: 0x64  ascq: 0x00
[ 1388.429350] end_request: I/O error, dev hdc, sector 1024
[ 1388.429378] UDF-fs: No partition found (1)
[ 1388.625844] hdc: command error: status=0x51 { DriveReady SeekComplete Error }
[ 1388.625857] hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
[ 1388.625862] ide: failed opcode was: unknown
[ 1388.626273] hdc: error code: 0x70  sense_key: 0x05  asc: 0x64  ascq: 0x00
[ 1388.626281] end_request: I/O error, dev hdc, sector 64
[ 1388.626308] isofs_fill_super: bread failed, dev=hdc, iso_blknum=16, block=16