I've been working on your problem for a couple of days, and I think I have found the cause. However I certainly don't have a solution for it!
I tried making a DVD like yours with a WMV intro and a MOV movie. Using Creator NXT 7's MyDVD it worked fine, but using Easy CD & DVD Burning 2's version of MyDVD I could not get audio from any of my software DVD players or my Blu-Wave player. It was there in preview, but I could not get it to playback in the DVD or ISO that the Redbox MyDVD made.
MediaInfo said there was an audio track there, but it was in PCM audio rather than the usual Dolby Digital AC-3 audio.
I made a number of DVDs with each software, and regardless of the source files [WMV, MOV, MP4, AVI, etc] NXT 7 always output AC3 audio, while Easy CD & DVD Burning 2 always output PCM audio. I went through two dozen random DVDs from my commercial DVD collection, and they ALL have AC3 audio and NONE have PCM. I have gone cross-eyed reading the results from search engines, but have not found any way to play these DVDs with their PCM audio.
We had quite some problems in earlier years, with the company cutting off the useful bits of Creator (including AC3 audio) to make the original Easy CD & DVD Burning, but I think they may have outdone themselves with this version. What use are the DVDs if you can't play the audio?
If anybody reading this knows how to play these DVDs with audio on PCs and DVD players, please step in and tell us. I can upload a small ISO to Google Drive (about 80 MBs) for a limited time (please PM me) if you want to poke a stick at it.