Havent used vectorlinux in a long time, but try using su and issuing the command.
If the cd mounts ok, and you can see the contents then, we know its mounting ok.
It may be that you need a utility to allow you to manually mount/unmount. Something like gkrellm would suffice for that purpose.
Alternatively to change the drive mapping in fstab, change:
/dev/cdwriter /mnt/cdwriter iso9660 defaults,noauto,ro,user 0 0
/dev/hdc /mnt/cdwriter iso9660 defaults,noauto,ro,user 0 0
But thinking about it, if linux says your cdrom is at hdd, then it probably is. If you change the jumper settings on it to Master, then linux should automatically change the /dev entry to hdc.