Horizonotal Accordion bouncing and clicking on active

Horizonotal Accordion bouncing and clicking on active

Hey guys... I have implemented a horizontal accordion and every time I click on an item and as it slides it shifts like it bounces.  how can I stop that from happening?

Second thing, when I click on an active slide, it closes and open again.  how can I have the active slide be disabled?

example of this is on www.jaypengo.com

Code is as follows:

jQuery.fn.extend({
  haccordion: function(params){
    var jQ = jQuery;
    var params = jQ.extend({
      speed: 400,
      headerclass: "header",
      contentclass: "content",
      event: "click",
      contentwidth: 510
    },params);
    return this.each(function(){
      this.opened = jQ("."+params.contentclass,this).filter(".visible").prev();
     
      jQ("."+params.headerclass+" a",this).bind(params.event,function(){
        var p = jQ(this).parent().parent()[0];
        if (p.opened != "undefined"){
          jQ(p.opened).next("div."+params.contentclass).animate({
            width: "0px"
          },params.speed);
        }
        p.opened = jQ(this).parent();
        jQ(p.opened).next("div."+params.contentclass).animate({
          width: params.contentwidth + "px"
        }, params.speed);
   
        return false;
      });
    });
  }
});