Someone suggest I head over to the #xubuntu channel on IRC. It turns out 12.04 was using /dev/dvd1 for the DVD drive and none of the media players were recognising this. In version 14.04 the DVD drive is now at /dev/sr0. In VLC it is only a matter of changing this in the preferences. Tools > Preferences > Input/Codecs.
Some other media players don't allow you to change the location so the partial solution is to put a systemlink fron /dev/dvd1 to /dev/sr0
Open up terminal and type:
sudo ln -s /dev/sr0 /dev/dvd