scsi cd drive locking up

[Graham Ashton <graz@mindless.com>]

I'm having trouble mounting CDs in my Toshiba SCSI CD drive. As soon as
I put a CD in (data or audio), the little green light on the front
flashes about 10 times, and then lights up permanently. The LED only
goes out when I eject the disk.

When I attempt to mount a (perfectly good) CD, I get;

  humbug:root> mount -t iso9660 /dev/scd0 /cdrom
  mount: block device /dev/scd0 is write-protected, mounting read-only
  mount: wrong fs type, bad option, bad superblock on /dev/scd0,
         or too many mounted file systems

I was away on holiday for a week, and when I got back I powered on my
machine and everything seemed to start up normally (but I'd left an
audio CD in the drive and the Adaptec 2940 BIOS spent a long time
trying to determine if the CD was bootable before it went on to detect
my hard disk).

Before I went away I was using cdparanoia without any problems, and
normal CDs were mounting without incident.

I tried fiddling with the permissions, changing them from;

  br--r-----   1 root     cdrom     11,   0 Dec  1 20:25 /dev/scd0

to;

  brwxrwxrwx   1 root     cdrom     11,   0 Dec  1 20:25 /dev/scd0

but (unsurprisingly) it's not made any difference.

Does it sound like a hardware problem, or could it be that something
needs resetting? Could it be Linux? A cold reboot doesn't seem to help.

TIA - I desperately want to do some more ripping!

-- 
Graham