Same answer from me re Imgburn and virtual drive.
Note that some DVD players also require the audio.TS file to be there as well (even though it's empty)
I have had occasions when it was missing and the DVD wouldn't be recognized as a DVD.
Assing that folder and reburning the lot (as data files) to a DVD worked.
The other thing to watch for is the bup files may need re-authoring if anything has changed - a little like trying to upload a torrent if you've, say, removed one track or altered the title etc- it won't work.
Now, the MP3 files.
I'm not too sure what you are saying here ???
You have copied your mp3 files to a DVD (as Data, I hope and not as a DVD)?
If you've burned a music DVD, you'll have to rip it back to the PC and then copy the mp3 files to a folder and reburn a CD from those files.
If you make an audio DVD, then it's a DVD and will play as an audio DVD.
Just burn the MP3's to DVD as a Data DVD for storing them and you can lift the individual tracks off it anytime. Burned as a DVD, you have to rip it to get them back again (just like ripping the audio track off any DVD).
Personally, I've never tried burning an audio DVD as (as you are trying to do) I just burn several CDs instead for playing (data DVDs for backup purposes only).
http://en.wikipedia.org/wiki/DVD-Audio
Sorry, a bit waffly there but I'm not quite sure if I got what you were asking.