[svlug] Strange mount problem

[Frank Arnold]

I have been testing the program " backuponcd"
to backup my system before upgrading from Mandrake 9.0 to 9.1
and it seems to work until the point when it tries to access the CD.
Then I get the following error message:
mount: wrong fs type, bad option, bad superblock on /dev/scd0,
       or too many mounted file systems

Any ideas as to what might be causing this?
Thanks in advance.
Frank Arnold