[dnanian]

Well, an I/O error can be caused by a few different thing: bad file data, bad metadata, actual bus interference and the like.

The first thing to try is to take this file and duplicate it in the Finder. If it duplicates successfully, delete the original, rename the copy and try the backup again.

If you get an error, the file is damaged beyond recovery and likely has to be re-ripped from the original CD.

If, after this, the backup doesn't work, it's possible that you're getting bus interference on FireWire -- if you have any other devices attached to the FireWire bus, try disconnecting all but the backup drive.

Let me know if that helps.