Have a completed, functioning A13 course running multiple videos throughout. I recently made a copy of the course to do some translation work on. Now when I go back to the source course, NONE of the videos play. I can see them in the slide by slide window, but upon preview or publishing they will not play- just a blank screen. What has happened and is there an easy fix (please don't tell me I need to re-install each of the movies!).