Follow-up:
I found a couple of solutions by following the link I mentioned in my post above. But the best one - for me - was the TiVo2MPEG program put out by TVHarmony.com ->
http://www.tvharmony.com/main/products.php. I didn't download the entire AutoPilot program, just the smaller TiVo2MPEG utility near the bottom of the screen.
I guess it embeds my TiVo media code somewhere in the file, like it says, but it's not visible on the screen so I don't really care.
But I also just ordered the Roxio Easy Media Creator 8 as an upgrade to my older Easy CD Creator 5 and it seems to include the Sonic MyDVD program which is supposed to deal with .TiVo files directly. But TiVo2MPEG is free and seems to work fine. At least the file loads into my VideoStudio 9 program so I can edit out the commercials. There is a feature in TiVo2MPEG that is supposed to edit out the commercials but I could never get it to work well.
I hope this helps anyone trying to do the same thing.
Pat