If you look in the mimeinfo.cache file, you will see that there is already a video link in there that will open ALL video files with videosuiteinterface.desktop Code: video/*=videosuiteinterface.desktop This means the problem lies in the browser itself, it isn't relaying the link properly to the N9, meaning that the the video file isn't detected and the video player doesn't open.
video/*=videosuiteinterface.desktop