Previews for audio clips wont play with space bar...

Hi, I have a project that I've been working with for a while...all of a sudden, when I hit the space bar while highlighting a clip in the project, it will not playback. This is only happening with audio clips (music).  Now this is only happening with audio clips, video clip previews playback fine with the space bar. To make things even more interesting, if I highlight an audio clip and scrub in the preview window, then all of a sudden the space bar works for starting and stopping. I've tried re-importing, restarting, bringing the same clips into a new project and still the same problem. Also tried moving the audio files to another drive and re-importing them, still nothing.

2017.1.1 v11