I have uploaded a media file to the program. I have inserted it into the master slide in my presentation. However, every time it switches to a new slide in my timed presentation, the song starts over. I have spent countless hours trying to figure out what to do to make it just continue on for the duration of the song without it starting over! 

This was posted to the forums by Dan Willard from EW Technical Support a while ago. 

"The audio file has to be set as a background element for it to play through the slides. When you add the audio file in the presentation, make sure you drag and drop it from the Media/Audio button to the Master slide on the left side. That should set it as a background. You can double check it by selecting the audio file and going to inspector and Media to make sure it's set as a background."

I just tried it and it worked for me.