It took me ages to resolve this, so I thought I'd pass it on.
I've been working on a pub where several pages play small videos. I have provided several buttons which will interrupt the playing of a page: Exit, Go To, Previous, etc.
When any of the pages containing videos were interrupted,
even if the video was not playing, the transition between pages momentarily left a very black distracting shadow which was the same size as the video object.
When I finally found a solution, it was so simple. That's often the way
Select the video object and open its Properties. Change Video Type to Rendered. That's it!
I've tested this on several video objects, and to paraphrase Dirty Harry:
It works for me.
I hope this might save someone some time.