no sound exported

I have a 30 second animation I’m trying add music and sounds too. I added a sound element and imported an mp3. it shows up in the timeline, and I can play it in “edit sound,” but when I export to Quicktime there is no sound on the animation. When I check the custom settings on export, I can check the “video” box and change things there, but the “Audio” box is not click-able. any ideas?

Is it possible for you to import your file as a .wav to see if that works?