use dvd decrypeter to get rid of the security code on the movie, keep in mind it takes up 8 gigs temporary hdd space till you finish burning. then try getting clone dvd (or nero but i find clone dvd does a better job compressing wile still being able to keep the movie's options). The temporary files take about 4.7 gigs hdd space too. once the movie is burned you can obviously delete these. hope this helps.
BTW dvd decrypter is freeware, just type it in on google and you should find a download for it.