SL2: Audio in layer won't synch - Help!

Hi folks,  I looked for an answer but didn't find this exact issue.  I have audio on the base and on several layers.  I finished synching the base and moved on to the first layer.  I can preview the audio, but when I click play at the bottom of the Timeline in order to synch my animations, I can't get any sound and nothing moves.  I've tried deleting the audio and putting it back, but nothing seems to work.  It acts like it's going to start, because it removes the animations, but then I wait and wait and nothing.  I've tried the Pause the baseline timeline as well.  I've also been successful having audio for multiple layers on other slides.  Any ideas?