Backup DVD problem

I just use Copy Cat to recover a vob file on my dvd disc. But the file size of it only has 6xxMB, It used to be .99gb
When I use dvdshink, it said “dvd shrink encountered an error and can’t continue. Fail to open file xxx.vob”

IS that any way to shrink the dvd?

Did you copy [B]all[/B] the files on the disc?