Audio won't load

I can give you the reason in my case.  I assumed when you brought in an audio file it was then a part of your project when in reality it seems to reference the location right.  Well I was cleaning up my folders and dropped them in an Audio folder.  Any slide that I looked at after doing that the file was "not found" - when I moved them back to the original location and started over, they were still not found with the exception of those slides I never attempted to view.  So essentially I had to re-load audio for two scenes, and the remaining 3 found their audio.  I'm glad though that loading the audio file by double clicking on the missing one keeps your captions in place.