This means that KSCD couldn't open your CD-ROM drive. The name of the device in the CDROM Devicecdrom field of the Kscd Configuration must actually refer to the block device associated with your CD-ROM drive. This will often be a hardlink to the appropriate IDE (/dev/hdx) or SCSI (/dev/sdx) device.
The device file normally belongs to user root in group root, and does not allow normal users to open it for reading, writing, or execution directly. This has nothing to do with the SUID (Set User ID programs use the setuid() function in the standard Un*x library to assume the identity of another user) mount command, which has no problems with permissions; KSCD must be able to get a read-only file descriptor referring to the CD device to control the CD-ROM drive and read raw data off the disk.
If you have the root password, you can fix this quickly and easily. Become root and type chmod a+r /dev/cdrom to allow any user on your system to read from /dev/cdrom. If your CD-ROM device is called something else, change the permissions on that device with the same procedure. If you don't have the root password, ask your system administrator nicely to give you read permission for the CD-ROM device.
See also the chapter on configuring KSCD