Comment 21 for bug 42023

Ok Martin, not an overburning issue.

Let's come back to Ben comments.
One said to check filesystems type once mounted with 'cat /proc/mounts' to confirm that the image filesystem is iso9660 and not UDF type.

Also Ben said that there must be tons of iso9660 checkers out there.
Well when I do apropos iso9660 I get:
paul@paul-desktop:~$ apropos iso9660
devdump (1) - Utility programs for dumping and verifying iso9660 images.
fs (5) - Linux filesystem types: minix, ext, ext2, ext3, xia, msdos, umsdos, vfat, proc, nfs, iso...
genisoimage (1) - create ISO9660/Joliet/HFS filesystem with optional Rock Ridge attributes
isodump (1) - Utility programs for dumping and verifying iso9660 images.
isoinfo (1) - Utility programs for dumping and verifying iso9660 images.
isosize (8) - outputs the length of a iso9660 file system
isovfy (1) - Utility programs for dumping and verifying iso9660 images.

The two most interesting seems to be:
isovfy from genisoimage package
and isosize from util-linux package

I also note that I can't find dvdread in ubuntu that you mentioned in:
https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.15/+bug/42023/comments/12
My search was:
http://packages.ubuntu.com/cgi-bin/search_contents.pl?word=dvdread&searchmode=searchfiles&case=insensitive&version=gutsy&arch=amd64