This may be redundant having posted this to several threads, but...
After reading and participating in countless threads about authoring a DVD from ReplayTV files, to me, the magic recipe is to record EVERYTHING at Medium Quality. It's an excellent compromise among quality, reliability, and size--I can fit almost 3 hours of Medium Quality content on a DVD.
If you have "Womble" and Ulead's "DVD Movie Factory 2", it's a simple matter of editing the file in Womble, saving the file, loading the resulting file into DMF2, and burning the DVD. A lot of us have had many difficulties with both High Quality and Low Quality recordings. Your milage may definitly vary on this, but my experience shows that Medium Quality is the way to go. Because DMF2 doesn't re-render a Medium Quality file, what you see on the ReplayTV box is what you see on the DVD. Video and Audio quality and sync is maintained, and the final result looks surprisingly good.
See shameless plug in my signature below for more details...
(Note: I'm using a model 5040.)