I upgraded from Edgy to Feisty and was able to use my two CD-Rom drives successfully.  I then reinstalled Feisty from scratch and had two problems.  The first is that /etc/fstab mentioned /dev/hdc and /dev/hdd, but those devices don't exist.  I updated /etc/fstab to refer to /dev/scd0 and /dev/scd1:

msl@edward:~$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# /dev/hda1
UUID=a6f5a82d-25c3-4497-9603-fe5ad2c54fd2 /               ext3    defaults,errors=remount-ro 0       1
# /dev/hda5
UUID=e9c7490a-9474-4e80-8c67-e7d367cabdc8 none            swap    sw              0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto     0       0
/dev/scd1       /media/cdrom1   udf,iso9660 user,noauto     0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0
/dev/sdb2       /mnt/b          ext3    user,noauto     0       0
/mnt/b/backups/hda1-20070528.img /mnt/oldhome ext3 loop,user,noauto     0 0
msl@edward:~$

This gave me access to /media/cdrom1.  But I still can't use /media/cdrom0, my CD-Rom burner, when I'm booted into Feisty.  It looks like quite a low-level problem:

msl@edward:~$ sudo hd /dev/scd0
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00005000
msl@edward:~$

(The CD in the drive when I ran this command was a Feisty desktop CD.)  dmesg includes this:

[  731.533053] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  731.533059] sr0: Current: sense key: Hardware Error
[  731.533062]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  731.533069] end_request: I/O error, dev sr0, sector 96
[  731.533072] printk: 2 messages suppressed.
[  731.533075] Buffer I/O error on device sr0, logical block 12
[  731.533081] Buffer I/O error on device sr0, logical block 13
[  731.533085] Buffer I/O error on device sr0, logical block 14
[  731.533088] Buffer I/O error on device sr0, logical block 15
[  731.533091] Buffer I/O error on device sr0, logical block 16
[  731.537557] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  731.537563] sr0: Current: sense key: Hardware Error
[  731.537566]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  731.537573] end_request: I/O error, dev sr0, sector 136
[  731.537577] Buffer I/O error on device sr0, logical block 17
[  731.539603] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  731.539607] sr0: Current: sense key: Hardware Error
[  731.539610]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  731.539616] end_request: I/O error, dev sr0, sector 144
[  731.539619] Buffer I/O error on device sr0, logical block 18
[  731.539624] Buffer I/O error on device sr0, logical block 19
[  731.539628] Buffer I/O error on device sr0, logical block 20
[  731.539631] Buffer I/O error on device sr0, logical block 21
[  734.091041] ISO 9660 Extensions: Microsoft Joliet Level 3
[  734.093195] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  734.093200] sr0: Current: sense key: Hardware Error
[  734.093203]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  734.093210] end_request: I/O error, dev sr0, sector 116
[  734.094436] ISOFS: unable to read i-node block
[  734.094444] ISOFS: changing to secondary root
[  734.109667] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  734.109671] sr0: Current: sense key: Hardware Error
[  734.109674]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  734.109680] end_request: I/O error, dev sr0, sector 560
[  734.110454] ISOFS: unable to read i-node block
[  734.263521] ISO 9660 Extensions: Microsoft Joliet Level 3
[  734.270966] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  734.270971] sr0: Current: sense key: Hardware Error
[  734.270974]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  734.270981] end_request: I/O error, dev sr0, sector 116
[  734.271833] ISOFS: unable to read i-node block
[  734.271839] ISOFS: changing to secondary root
[  734.286036] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  734.286041] sr0: Current: sense key: Hardware Error
[  734.286044]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  734.286050] end_request: I/O error, dev sr0, sector 560
[  734.286860] ISOFS: unable to read i-node block
[  748.419199] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  748.419206] sr0: Current: sense key: Hardware Error
[  748.419209]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  748.419216] end_request: I/O error, dev sr0, sector 96
[  748.419220] printk: 2 messages suppressed.
[  748.419223] Buffer I/O error on device sr0, logical block 12
[  748.419231] Buffer I/O error on device sr0, logical block 13
[  748.419234] Buffer I/O error on device sr0, logical block 14
[  748.469482] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  748.469489] sr0: Current: sense key: Hardware Error
[  748.469492]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  748.469499] end_request: I/O error, dev sr0, sector 232
[  751.547730] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  751.547736] sr0: Current: sense key: Hardware Error
[  751.547739]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  751.547746] end_request: I/O error, dev sr0, sector 40
[  751.547749] printk: 44 messages suppressed.
[  751.547752] Buffer I/O error on device sr0, logical block 5
[  764.871503] sr 1:0:0:0: SCSI error: return code = 0x08000002
[  764.871509] sr0: Current: sense key: Hardware Error
[  764.871512]     Additional sense: Logical unit communication CRC error (Ultra-DMA/32)
[  764.871519] end_request: I/O error, dev sr0, sector 40
[  764.871521] printk: 22 messages suppressed.
[  764.871524] Buffer I/O error on device sr0, logical block 5
[  764.871530] Buffer I/O error on device sr0, logical block 6
msl@edward:~$

I can, however, boot from the desktop CD, so I know that the CD-Rom drive is working properly.

I'm fully updated:

msl@edward:~$ uname -a
Linux edward 2.6.20-16-generic #2 SMP Thu Jun 7 20:19:32 UTC 2007 i686 GNU/Linux
msl@edward:~$

If I place a CD into the first CD-Rom drive, KDE's usual dialogue box appears -- open in new window, copy CD, do nothing -- but double-clicking 'open in new window' dismisses the dialogue box without actually opening the CD in a new Konqueror window.  This tells me that KDE knows a CD has been inserted, but can't read the root directory.

I've attached the output of `lspci -vv', `lspci -vvn' and `lshw', all run as root.  The CD-Rom writer that doesn't work is the LITE-ON device shown in `lshw'.

Many thanks for looking at this.  Please let me know if I can do any more to help diagnosis.