Found out how to make a real DVD from a VIDEO_TS folder.
makehybrid -udf -udf-volume-name "name of dvd" -o name_of_iso.iso path_to_directory_containing_VIDEO_TS
It is important that the directory containing the VIDEO_TS directory doesn't have any other files in it, otherwise the DVD player seems to treat it as a data DVD.
This from :
http://www.macosxhints.com/article.php?story=20070612161317338&query=burn%2Bdvd