I'm Burning using Nero 8 by selecting the option in DVD Burning Options in the configuration section of DVD Fab.
I will be trying the imgBurn on my next one to see if that does anything in Movie Only & Custom.
I have checked the temp dir where DVDfab stores the movie before burning and it did not create the Audio_TS folder there either.
I'll get back to you tomorrow on this and let you know what I find.
(I would use the VSO burn but I have had a costers disks made when doing those for some reason, not all but a few here and there that I had to remake.)