I'm using Kubuntu 7.04 and I have a backup CD with a bunch of saved programs that I can't open. I've tried cleaning and it almost mounts but then fails. Is there a good .deb data recovery program someone could recommend to solve this problem? Thanks.

If this data is on a cdrw disk you may have a problem. First try another computer and see if it'll read the disk. I've had cds that would read in a player and the next cd wouldn't but it would read on another cd player.

No, it's on a regular CD-R. I burned it using K3b and I can't see a scratch on it. Weird and frustrating.

Try this:
Let's assume your /etc/fstab shows this entry for the cdrom drive: /dev/cdrom /media/cdrom, where /dev/cdrom is the cd drive, and /media/cdrom is the mount point.

From the command line, as root: mount /dev/cdrom /media/cdrom. Do you get any error messages? What are they?

Immediately after that, as root, run 'cat /var/log/messages | tail' without quotes to see the last twenty lines of /var/log/messages. Twenty line is the tail default. You can increase the number of lines with tail -n xx, where xx is the number of lines to look at. What errors, if any, do you see?

If there is a damaged disk, you can try to rescue data with ddrescue utility.

I highly doubt it is the CD-R causing an issue, probably the optical drive.
I would use dd or ddrescue to make an ISO image of the CD-R and mount the image as a drive. If you have a dodgy optical drive, ddrescue should eventually get a bit for bit image. Cleaning the laser with a lens cleaner may help in some cases. Below are the steps I use:
Then the contents will be available in /mnt/cd, but you're not trying to read from a dodgy drive no more. You can also make the image using a Live CD in someone else's computer onto your 1GB pen drive and mount the image in the pen drive back at the ranch.