Q: Audio no longer audible

You might get better help in the DVDSP forum if it still exists.

when I was using DVDSP4 ( a l on g time ago) I found it was usually easier to rebuild the project by re-importing the media instead of relying on the application to refresh the links.

Are you first going to Compressor to create separate audio and video streams or are you having DVDSP do the encoding?

To David's advice about the DVDSP forum, there isn't one per se, but  questions on DVDSP are typically answered in the FCS forum, where I see you have posted.

Russ