I'm just trying to be funny.  
I'm using Vegas Pro 8.  I film in HD NTSC 5.1 720 x 480.  I recently learning how to record audio to the timeline using the arm record etc.  Once the WAV file is saved it plays great in the timeline as I  narrate some photos.  However rendering to Mpeg4 in with the surround settings, I've been rendering successfully until now.  
 
I had to export the WAV file to Audacity, convert it to Mp3 and then re-insert in the timeline.    It worked.  Seems like a lot of work.  
Any suggestions? 
Of course I'm a FNG.  
Thanks in advance. Joe