event.layerX and event.layerY are broken and deprecated in WebKit. They will be

 // solution
 //The temporary fix is to run this code before you do any event binding via jQuery:
 //临时的解决方案，将下面这段代码放到JQuery事件绑定之前
   
   $(document).ready(function(){
       
       $.event.props = $.event.props.join('|').replace('layerX|layerY|', '').split('|');
 
     ....

    });