Dox,
I haven’t run into the same situation before, but the best answer I can find right away are dependent on which device the media was captured on, this article is saying that if you used a<span>Sony or JVC camcorder or Apple’s iPhone or iPad. Then the m4a files should behave well, any others may have issues. I know it doesn’t explain much, but we’ll keep digging.</span>
<span></span>ref:http://www.bigasoft.com/articles/how-to-import-mp4-to-premiere.html
The article refers to .mp4 whose audio files should be .m4a’s
ref:http://www.m4a.com/m4a-m4p-files/
Hopefully this provides some explanation, but your work-around sounds like perfect, but frustrating since you shouldn’t have to.
-Jackson
