html - jQuery isn't loading function on hover -

i have following code: http://jsfiddle.net/7pm2b/167/

this jquery code:

    $('#change_opacity').hover(function(){     $(this).trigger('startrumble');     }, function(){     $(this).trigger('stoprumble');     }); 

what trying achieve on hover want image shake, i'm using jrumble library "shaking" can't seem on hover working. missing?

demo

this works:

$(function () {     $('#change_opacity').jrumble();      $('#change_opacity').hover(function () {         $(this).trigger('startrumble');     }, function () {         $(this).trigger('stoprumble');     }); }