much better to use compressor and dvdsp. Not brain surgery.
Export your edit from fcp using file: export: quicktime movie (not quicktime conversion). Bring that file into dvdsp and apply the appropriate dvd preset. That will produce 2 files; an m2v (video) and an ac3 (audio).
Bring these two files into dvdsp and drag them both to a track and make the track first play. Build an Format.
Do some searching here and I think there are links to some simple tutorials that go in to more detail. Post back if you have any questions or need more details.