Excellent explanation, ggrussel! I hadn't even considered the possibility of the menu itself having duration. I thought of it as static.
Sorry for the overly(?) concise description of the problem on my part. And, many thanks for your considerate response, Sir.
I specify a file (tried wav and mp3 files) for (Main) Menu audio track. When I burn and play the DVD, I only get 15-20 seconds of a the track which is a 4 minute track. Is this a limitation? Or, have I made a mistake?