Multiple Videos on same slide superimposed

[buddhapups]

As a long time Powerpoint user I have on many occasions placed more than one movie on the same slide and played them simultaneously. Now when I try this even though the movies are placed on the slide in different locations they all play in the first box on the left side of the slide and if running at the same time superimpose themselves on each other. I have no idea why this is happening. Please advise.