[ddouglass]

That I am not sure I can answer. I don't use videos at all so do not have any experience with either plain VCDs or Multiplexed ones. Did they work correctly in previous versions or have they never worked for the Multiplex?
I do know that the next release which will be a ways off, is planned to have Hoster set up to add the video files to Hoster's database with BookIDs. The multiplex will be one thing they will need to look into while that is being developed.
If this just started I suggest you send in a Support Email with the problem and they can start looking at it now. I would not expect an immediate answer to the problem but at least they will be aware of it to try to get it working with 4.20.