This how to will help you to make an iso image from your CDROM
1. Insert CD to be copied
2 Open a terminal
3 $ sudo umount /dev/cdrom0
(unmount the cd . Be careful about cdrom0 . It can be some thing else on your system. running mount with out arguments can help you to find out the cdrom device.)
4 $ sudo dd if=/dev/scd0 of=file.iso bs=2048 conv=notrunc
(the /dev/ listing may vary so be sure which is your cd. Also make sure that you have sufficient free space on the hard disk)
4. Once complete use your favourite .iso (k3b, brasaro, etc.) to burn the image back to another disk.