Video runs in webpage but not in smartphone

I have just learned that though it works well in iphone, it is still having some problems in the ipads, the one which has done the last updates.

Two people tested with their ipads and these were the found :

  1. The one who did the latest upgrade, video is loading but after a few seconds stopping abruptly, hanging the webpage.
  2. The one who did not do the last upgrade, for him the video is working perfectly.

Any idea ? Sounds strange.