mp4 vod sample issue

After about two years of working with FMIS, we're starting to look at live streaming and vod features.  To that end I've finally tried to check out the vod samples, and I'm running into an issue getting mp4 video to play.  My first error had to do with neglecting the "mp4:" before my movie name, but now what happens is that the service seems to connect, shows "loading" under the controls, then shows "playing" followed almost immediately by "stopped".  I click the play button, and in rapid succession see "buffering", "playing" and then "stopped" once again.  I'm not sure what to make of this, but for whatever reason my mp4 movies refuse to play, although they do seem to load ok.

If anyone's seen this behavior and can help me understand it, I'd really appreciate it.  Thanks in advance for any assistance.