This is the name of a 2008 discussion without a proper solution.
I have the same issue with Presenter 10, quite a few years later...
I'm importing mp4 videos in the sidebar video with medium quality option but when playing the presentation the slide starts without waiting the video to fully buffer.
Control preloading is enabled
Here is the presentation OGC Indoor GML
Thanks in advance
Have you tried placing the video on the side bar as an FLV?
Retrieving data ...