I submitted this bug and I noticed some slightly different entries in the message log when I tried to mount a 5th CD-RW disk on Ubuntu 8.10 that was created on Ubuntu 8.10.  

[10859.673944] UDF-fs: No VRS found
[10859.744303] ISO 9660 Extensions: Microsoft Joliet Level 3
[10859.797482] ISO 9660 Extensions: RRIP_1991A
[10943.189214] sr0: CDROM (ioctl) error, command: Start/Stop Unit 1b 00 00 00 03 00
[10943.189227] sr: Sense Key : Hardware Error [current] 
[10943.189230] sr: Add. Sense: Media load or eject failed
[11017.252507] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11017.252514] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11017.252519] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11017.252525] end_request: I/O error, dev sr0, sector 486776
[11017.252530] Buffer I/O error on device sr0, logical block 121694
[11023.664163] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11023.664171] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11023.664175] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11023.664180] end_request: I/O error, dev sr0, sector 486776
[11023.664185] Buffer I/O error on device sr0, logical block 121694
[11030.101587] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11030.101595] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11030.101599] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11030.101604] end_request: I/O error, dev sr0, sector 486776
[11030.101609] Buffer I/O error on device sr0, logical block 121694
[11036.513403] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11036.513409] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11036.513415] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11036.513420] end_request: I/O error, dev sr0, sector 486776
[11036.513425] Buffer I/O error on device sr0, logical block 121694
[11042.927837] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11042.927845] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11042.927849] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11042.927854] end_request: I/O error, dev sr0, sector 486776
[11042.927859] Buffer I/O error on device sr0, logical block 121694
[11049.337058] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11049.337066] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11049.337070] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11049.337074] end_request: I/O error, dev sr0, sector 486776
[11049.337079] Buffer I/O error on device sr0, logical block 121694
[11055.748857] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11055.748864] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11055.748868] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11055.748872] end_request: I/O error, dev sr0, sector 486776
[11055.748877] Buffer I/O error on device sr0, logical block 121694
[11055.849805] cdrom: sr0: mrw address space DMA selected
[11055.894074] cdrom open: mrw_status 'not mrw'
[11062.364162] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11062.364168] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11062.364174] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11062.364179] end_request: I/O error, dev sr0, sector 486772
[11062.364184] Buffer I/O error on device sr0, logical block 121693
[11068.780243] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11068.780250] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11068.780254] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11068.780258] end_request: I/O error, dev sr0, sector 486776
[11068.780263] Buffer I/O error on device sr0, logical block 121694
[11075.189488] sr 5:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
[11075.189495] sr 5:0:0:0: [sr0] Sense Key : Hardware Error [current] 
[11075.189499] sr 5:0:0:0: [sr0] Add. Sense: Timeout on logical unit
[11075.189504] end_request: I/O error, dev sr0, sector 486776
[11075.189509] Buffer I/O error on device sr0, logical block 121694
[11075.245963] cdrom: sr0: mrw address space DMA selected
[11075.248497] cdrom open: mrw_status 'not mrw'
[11075.270069] UDF-fs: No VRS found