This is not a problem with the Microsoft software. This problem is due to the fact that "old" Apple Cinema displays are no longer supported by Apple. Because of this, someone from the Microsoft forums reported this problem to Apple, back in Jan. 2014, hoping that Apple would address it:
http://answers.microsoft.com/en-us/mac/forum/macoffice2011-macpowerpoint/movie-f iles-embedded-in-powerpoint-for-mac-2011…
I can report that, to date, this problem has not been addressed by Apple. This is a serious issue for me because this bug is sabotaging my ability to create screencasts with Powerpoint for Mac 2011. I'd like to request that Apple should fix this bug as soon as possible.