missing CD-ROM drive

[ben miller]

for some reason unknown to me, my CD-ROM drive has stopped mounting. Trying to 
mount it via: sudo mount /media/cdrom0/ -o unhide returns a message which 
says 'special device /dev/hdb does not exist.'

LIkewise, trying to mount /dev/hdb directly returns the message that the 
address can't be found in mtab or fstab. Yet, here's the contents of my fstab 
file:

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/hda5       /               ext3    defaults,errors=remount-ro 0       1
/dev/hda4       none            swap    sw              0       0
/dev/hdb        /media/cdrom0   udf,iso9660 ro,user,noauto  0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0


Any clues?

Thanks,
Ben