check your /etc/fstab file to see if there is an entry for your cd-rom drive.
Code:
/dev/hdc /media/cdrom0 udf,iso9660 ro,user,noauto 0 0
Something along those lines should be there. Check under /media to see if there is a folder for your cdrom drive, and if there isnt, create the /media/cdrom0 folder that was in the fstab entry.