Shannon may be right, but I'll offer another possibility.

Take a look at the file structure of the DVD on your computer, through Windows Explorer. If you have a Video_TS directory, then your DVR is "reauthoring" your mini DV input. If not, you will have confirmed what Shannon says.

However, I have recorded a number of movies from my Tivo (ms-dvr files) to my DVR and it produces a standard DVD in that it has a Video_TS directory with .ifo, .bup, and .vob files. However, it also produces a Video_RM directory with a backup .ifo and a couple of other files.

What my DVD recorder-made dvds to do not not have, however, is an Audio_TS directory. Now, while these are empty directories on all but audio dvds, the reason they are there is because some, especially older, dvd players will not play the dvd unless the Audio_TS directory is present. That is most likely your problem, in my opinion.

There's a dvd recorder forum over in another section of CD Freaks:

http://club.cdfreaks.com/forumdisplay.php?f=106