Powerpoint video problems

I just did a quick test with a .mov file, and if you save the project as a .pptx file, it works fine. If you save as an old-school .ppt file, you get the poster image and no video. It explicitly warned me that some features of the file weren't supported in the format when I tried to save as .ppt, but I'm guessing you checked the "don't show this message again" box at some point in the past, so you didn't get that warning.

If you select "Compatibility Report" from the View menu, it will tell you exactly what the problem(s) might be with the current document. In the case of a presentation with a video in it, I quote:

Audio or movies that are embedded in this presentation will be converted to pictures when the file is saved in an earlier format, such as .ppt, .pot, or .pps.

Click to expand...

So your only option, it would seem, is a .pptx file. I'm almost positive that earlier versions supported this with .ppt, so presumably they removed the ability from 2011 Mac.

[Edit: Yep, Powerpoint 2008 can save a .ppt with a movie, although notably it doesn't embed the video file within the .ppt, so it won't transfer well, and I seem to remember there being cross-platform problems with video-embeds on Windows. The .pptx, in contrast, actually contains the whole video, so it's a huge file, but robust in terms of copying it to another computer.]