I did not quite understand your post - cdrom drives are managed by libata in the newer kernels and do not appear as hdX anymore but as sdX now. Furthermore I would bet support for the cdrom filesystem iso9660 is build in the kernel and NOT as a module.
I am quite sure that the herd3 CD will boot on our machines again - the problem is fixed (at least for me and another bug reporter in kernel bugzilla) in kernel-2.6.20-rc5. -- cdrom not detected in feisty https://launchpad.net/bugs/76598 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
