my reply might have some stupid questions in it, but .....
#1 - drives normally don't just 'stop' working... unless thier bad.
(won't read, won't spin up, etc).... have you tried anather drive?
#2 - did you do anything right before it stoped working?
(edit a or some /etc files?, recompile the kernel? etc?)
#3 - does the drive work for other users? root?
#4 - happens on all CD's ? data? CD audio?