Thanks for clearing up the confusion. Your problem is tied to the ata_piix -> piix switch described in Bug #116996 (which caused the device rename) that happened with 2.6.20-16 on ICH4/ICH5 controllers. Because the the CD drives tend to be referenced using a /dev/ syntax (and don't make use of the /dev/cdrom symlinks) as UUIDs can't be used, there is no way they could survive such a rename. Could you upload your /etc/fstab file please?
I have a feeling your issue is different to that of mcgyver's. Please spin off a new bug (and readd the information you have here to it) and then post a link here to the new bug.