jquery mobile animate() problem

jquery mobile animate() problem

Hi, there

I am developing a new web app for android tablets and have such a problem.
I use jquery animate() function to animate the height of a div. Everything is ok when I test it on PC browsers, but animation is slow and choppy on tablet's opera mobile and android browser. Here is the animation:

        <script type="text/javascript" src="js/jquery-1.8.2.js"></script>
        <script type="text/javascript" src="js/jquery-ui-1.9.1.custom.js"></script>
        <script type="text/javascript" src="js/jquery.mobile-1.1.1.min.js"></script>

      <script>
            $(document).ready(function() {
                $('#animate_trigger').live('click', function() {   
                    $('#animated_div').animate({ 'height': '300' },500);
                });
            });
      </script>
      <div id="animated_div"></div>
      <div id="animate_trigger"></div>

      Thanks in advance