Hey rack04!
Not sure if I'm following, but I'm assuming you want it much like a 3xDVD (that is, a DVD dual or single layer disc with the movie in HD, such as 720p or 1080i/p). In that case, you would probably need either Sonic Scenarist (either SCA or ACA) or Ulead DVD MovieFactory 6 Plus with the HD Pack addon (much cheaper, about $90 as opposed to much, much more for Scenarist).
In my case, I use the exact same profile as you have been doing, but instead of muxing the video and audio, I would keep the video as RAWAVC (which should output as a .264 file), and then I use H264info with only the '3:2 Pulldown' option checked, which should flag the video as 29.97fps, which is crucial for any authoring program. Next, I mux the pulldown video with the audio in TsMuxer, selecting the option to mux with 'TS muxing' output.
Once that's done, and assuming you have MovieFactory 6 Plus with the HD Pack, I would then select HD-DVD Standard from the main menu, then select 'HD-DVD on DVD 4.7G' or '8.5G' from the clickable box in the lower left corner, and drop your .ts muxed file into the timeline.
I have a Venturer SHD7000 DVD player, which is in reality a rebadged Toshiba HD-A3 (which is what you have) which even uses the same firmware (and I believe was built by Toshiba), and with the 3.0 firmware version, I've noticed that you can create chapters in MovieFactory without any problems playing back, so if you prefer to do that, by all means do so. Using those steps, I've had no trouble creating HD discs on DVD media, which ironically even works for backing up Blu-ray movies that you may own if you have a computer drive that reads those.
Of course, if anyone else knows of any free alternatives to authoring, or other programs, I'd love to hear those as well; this seems to be a dying art with Blu-ray winning the format war, but a lot of us have HD-DVD collections and players (got mine for $69 Canadian a couple months ago) and would like to make use of them still.
Good converting to all!
P.S. Don't forget to uncheck the 'Create Menu' option on the main timeline page if you're just wanting the movie to play without menus; it adds extra size to the disc output, which might make or break fitting it onto DVD-R/+R SL/DL media.
P.P.S. Sorry, I forgot to mention, you may want to downconvert any DTS or AAC tracks to AC3 format, MovieFactory seems to have an issue with not wanting to accept anything other than AC3, at least in my experience. Good luck!