There currently is no way to automatically validate all the links but since it is a good idea I have added it as a hidden command. Download DVDpedia beta 32
and then hold down the option key and click on the main help menu, there will be an option to validate the links. If some files are not located DVDpedia will create a new collection and place any entries it was unable to locate the link for in that collection. Be sure to mount any necessary external hard drives and or network media that contains files before running the command.