Audio in timeline of FCP X project drops out

The audio in the timeline of this project cuts out in entirety at the same point (see arrow in pic) when I Export to a DVD or QT movie file. I've tried re-starting and trashing preferences to no avail. This is a new development that just started happening today. I've exported this project many times previously without a problem. I've even re-cut in the sound effect that occurs at the same point.

A possibly related problem just cropped up. I made a Snapshot of the above timeline. When I attempted to Export to DVD as a Disk Image, it stalled at 66% and I got the following message: "There was an error creating your disk image."

Thanks,

Phil