Welcome to LQ.
You are talking about this behavior:
$ sudo mount ubuntu.iso /mnt -o loop
[sudo] password for simon:
simon@indigo-prime:~/Projects$ ls /mnt
autorun.inf dists isolinux pics preseed ubuntu
casper install md5sum.txt pool README.diskdefines wubi.exe
/dev/loop0 on /mnt type iso9660
So the iso is actually mounted - you have access to the files? How is this less than useful?
Anyway, this behaviour is run by udev.
It makes sense because mount only works on block devices - eg. not isos. The mount command is correctly displaying that /dev/loop0 is what it has mounted - which is what the -o option does.
It is usually considered good practise to name the mountpoint
for the iso.
sudo mount -o loop ubuntu.iso /mnt/karmic-iso
What are you trying to do that needs you to keep track of the actual filename?
Why are you logged in as root?