Web Object video inserts silence before playing

I have a couple of YouTube videos that I have embedded using Web Objects.  They are set to play automatically after the previous slide advances automatically.  Unfortunately, 10-20 secs of silence seems added to the slide before the video shows up on the screen and you can see the Articulate player slider moving like there is content.  So I checked in the Audio Editor and sure enough, I can see the 10-20 secs silence showing on the slide, just like I added in the silence myself (I didn't).  I have tried deleting the silence, but each time I go back into the editor, it is back again. There are no animations or anything on this slides apart from the video.  Nothing is timed to delay.  Slides without audio or animations etc are set to display for 0.1 secs.  Please help!