apt-cdrom on Gutsy

[MJang]

Folks, 


I'm trying to test the apt-cdrom command on my Gutsy 64-bit system. I
run the 

sudo apt-cdrom -d /media/cdrom0 add 

command, and get the following messages

Using CD-ROM mount point /media/cdrom/ 
Unmounting CD-ROM 
Waiting for disc... 
Please insert a Disc in the drive and press enter 
Mounting CD-ROM... 
Identifying.. [some md5sum] 
Scanning disc for index files.. 

Found 0 package indexes, 0 source indexes, 0 translation indexes and 1
signatures 
E: Unable to locate any package files, perhaps this is not a Debian Disc

I get log messages like Dec 26 17:38:29 ubuntuserver kernel: 

[13775.502213] UDF-fs: No VRS found

I've tried it with an ISO as well, mounted on /misc, configured
in /etc/fstab, and get the following errors in /var/log/syslog

Dec 26 17:18:00 ubuntuserver automount[7394]: failed to
mount /misc/.disk 
Dec 26 17:18:00 ubuntuserver automount[7395]: failed to
mount /misc/.aptignr 
Dec 26 17:18:00 ubuntuserver automount[7396]: failed to
mount /misc/Release.gpg 
Dec 26 17:18:00 ubuntuserver automount[7397]: failed to
mount /misc/Packages 
Dec 26 17:18:00 ubuntuserver automount[7398]: failed to
mount /misc/Packages.gz 
Dec 26 17:18:00 ubuntuserver automount[7399]: failed to
mount /misc/Sources.gz 
Dec 26 17:18:00 ubuntuserver automount[7400]: failed to
mount /misc/Sources 
Dec 26 17:18:00 ubuntuserver automount[7401]: failed to mount /misc/i18n

It's as if apt-cdrom expects to find .disk, .aptignr, Release.gpg and so
on in the base directory of the mounted CD (or ISO0. 

Am I missing anything, or should I file a bug report?

Thanks,
Mike