Jquery UI Slider Events not raised

Jquery UI Slider Events not raised

OK.. Here is the problem. I have downloaded the UI slider from Jquery website. The slider shows up fine. The slider moves fine.. BUT.. none of the callbacks are being called. i have searched high and low for this but oculd not find anything. Should i add that Im a noob to Jquery?

Here is the code that i use
   <script src="js/jquery/jquery-1.3.1.js" type="text/javascript"></script>
   <script src="js/jquery/ui_core_slider.js" type="text/javascript"></script>
   <script type="text/javascript">
      $(document).ready(function(){
         $('#slider_callout').hide();
         $('#slider1_bar').slider({
            handle: '.slider_handle',
            stop: function (e, ui) {
               console.log( "stopped" );
            }
         });
      });
   </script>
<!--- OTHER HTML HERE --->
      <div class='slider_bar' id="slider1_bar">
         <div id="slider_callout"></div>
         <div id='slider1_handle' class='slider_handle'></div>
      </div>


Any help is appreciated
Thanks
Cartic