[Plugin: MediaElement.js – HTML5 Video & Audio Player] Control audio play/pause from external ev

HI, I try to play pause audio files from external events.
I put buttons to simulate this as you can see on this web af2012.org
This commands work well in chrome but not in IE or FF.
There are any solution ?

http://wordpress.org/extend/plugins/media-element-html5-video-and-audio-player/