The audio won't play for the video you've dropped into a Drop Zone, ruff. That's a purely visual function.
To add an audio background to a DVD menu, you need to click on the background in the Disc Layout window and then select the button to browse to your audio selection.
If the selected AV file is muxed, i.e. contains both Audio and Video, the easiest way to handle what you need is to rip the Audio from that AV file. The freeware audio-editor, Audacity, can do that for you. Then, just Save your file as PCM/WAV 48KHz 16-bit. Link that WAV file to your Menu, per Steve's directions.
I should have been more clear... the music that disappears, that I would like to bring back, is not the audio associated with the clip I put in the drop zone, it's the music that comes with the template itself. As soon as I drop any media into the drop zone, the music completely disappears. Strangely, though, the music is still there for all of the scene selection pages, it's only missing from the main menu.
While we're on the subject... any way to get more than 29 seconds on the audio before it loops? Just playing around I put some other audio in there but they all loop right at 29 seconds and it sounds silly.
Do you guys even use the built-in templates or do you export into more robust authoring software like Encore?
There are a number of additonal DVD templates available at Muvipix.com. Many are complimentary, and others are available for premium subscribers.
No, you can not exceed 30 seconds for a loop on your DVD.
As for your audio, what happens if you click on the background of your menu page in the Disc Layout panel and click the Audio's reset button?