Cdrom drive problem lenovo 0687

[squareyes]

Hi all,
have a strange problem re combo cd/dvd drive on Lenovo laptop
Drive works to install both Win Xp and Ubuntu (tried 7.10  and 8.04)
same results, works to install systems, but once installed is no longer 
accessible in either XP or Linux.


Have just updated bios
on trying to mount cd drive I get

squareyes at here-laptop:~$ mount /media/cdrom0/
mount: /dev/scd0 is not a block device

etc/fstab

 # /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# /dev/sda1
UUID=5423422d-7205-4c55-8d6b-813d38e24a00 /               ext3    
defaults,errors=remount-ro 0       1
# /dev/sda5
UUID=87923e95-585c-412a-9fec-a6249a2f0b46 none            swap    
sw              0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec 0       0


What am I doing wrong??

Many thanks
Take Care
Winton