Sorry (maybe a bit slow today) but doesn't the manual state that after setting the source the video would be paused and would need the 'Play' action to start it?
[quote:2us8lb8t]Set source
Set a different video file to play. As with the object properties, three formats can be specified. Setting the source does not automatically start playing the video; use the Play action to start it after changing the source.
So wouldn't this mean it's working correctly?