The "type" of the /dev/cdrom device is "audo" - it sounds like a typo... Google on the term found very little occasions of this appearing on the web, mostly with questions of "is this a typo?" or failed mounts because of an unrecognized type... If it's NOT a typo, IMHO this type should be explained in the Handbook...
oops - why didn't google find this bug :( *** This bug has been marked as a duplicate of bug 177990 ***