Flash movie won't play on one slide in preview

Hello.

I am using an avatar creation software (Media Semantics) and importing the character with audio as a flash movie into Aritculate.  It has been working fine for several weeks, until today.  The timing was off (the avatar finished speaking LOOONG before the slide advanced) so I attempted to insert silent audio for the desired slide duration.  This worked on all slides that I tried this with--except ONE! 

The movie (avatar) looks and sounds perfect in PPT.  But when I preview the slide in Ariculate Presenter, the movie is not visible at all.

To resolve the issue, I have tried:

(1) Deleting the flash movie from the PPT slide and from Articulate, and creating a completely new movie...and then inserting that new movie into Presenter.

(2) Cutting and pasting all other animations on the slide onto a completely new slide, and then importing the new flash movie.  (I have 12 very detailed animations in the slide -- not including the avatar--so I am reluctant to completely delete all elements on the slide and start over.  It took me over an hour to create and time those elements.)

(3) Shutting down the computer, and rebooting. (Hey, I thought, "Why not?")

(4)  Checking all settings to ensure they are correct.

This is extremely frustrating, because the avatar worked perfectly on that slide until I tried to fix the timing issue.  The avatar works fine on all other slides --including other slides where I have inserted silent audio to fix the timing issue.

Any suggestions?