Has to be a simple explanation, this is obviously not the norm! Never had any issue like that myself.
Are you using Dynamic Link from Premiere? Or exporting assets from AME to import into Encore?
Like John said, screen shots are great, or at least give us a detailed workflow. "I have no sound" doesn't give us much to go by.
How are you testing the DVDs, computer or set-top player?
Safe Harbor Computers
Perhaps I posted too soon... I went back, re-rendered the whole project (including the large files I was avoiding re-rendering) in Premiere, and rebuilt the encore file from scratch (for the 4th time) and for some reason it took.
I had heard that if there were different bitrates on your audio this problem could occur so when all the bit rates and video files showed up the same I figured that wasnt it. I had initially re-rendered a few of the smaller clips in hopes that would remedy the problem but after burning multiple DVDs and testing them in my TV player it still turned up with no-audio. I have no clue why, but when I re-rendered everything that fixed it...
Thanks for your interest.