EDIT: see my new post about this here:
Linux DVD conversion to h264 aac mp4
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Simply use ddrescue…to install in Ubuntu:
sudo apt-get install gddrescue

To use:
ddrescue -d /dev/cdrom output.iso

It is by far the best/easiest program I’ve seen for rescuing data and it will recover everything possible. (It works great on CDs and DVDs)