I'm not all that familiar with Mandrake, so please don't flame me if things are set up differently from RedHat, but in RedHat you could go to the /dev directory and take a look at the cdrom device. I think it should be similar if not the same in Mandrake. Use ls -l /dev/cdrom* and see if it's a link. If it is, then also at whatever it's pointing to. Check the permissions on these files. If they're owned by root, but somehow had their permissions corrupted, that could cause your problem.