Comment 8 for bug 12491

As of version udev-0.050-3ubuntu3, the installation put only one symlink entry
under the /etc/udev/rules.d/ directory, which points to /etc/udev/udev.rules.
This configuration won't create /dev/cdrom link automatically. The packager
should consider adding extra symlink, either to /etc/udev/simple-cd-alias.rules
 or to /etc/udev/cd-alias.rules (both of which are installed already, just not
linked). This will solve the problem