Thank you for the reference link, Jeff, it provided me with a method for a "successful" workaround:
http://forum.cyberlink.com/forum/posts/list/17273.page
In my case I was using a static image for the Title/Chapter menu. I simply created a new project, dragged my image to the timeline, and set the duration for 1 minute. Then I generated a video file out of the project, which I then imported as my Title/Chapter background video in the Menu Designer. I selected my background music on the Title/Chapter menu, set the keyframes to the 60 second chunk of music that I wanted, and it seems to have had the effect I desire.
Crazy-ackward workaround though - I would have never tried that on my own. I wish Cyberlink would put a little more emphasis on their DVD menu designer component of PD. Seems strange that it would lack so much functionality and flexibility, when the Edit component is so powerful.
Also sorry for the duplicate post. I posted the first one, then went to find it a little later but never did.