Jquery table sorter and IE8

Question

I am using this code and everything works fine in firefox. But on IE8, the class for TH is not set, so no arrows show up. Anyone had this problem? I cannot find anything wrong with this code. Thanks.

var myTextExtraction = function(node)  
    {  
        return node.getAttribute('sorting');
    }

    jQuery("#myTable").tablesorter({textExtraction:  myTextExtraction ,
        headers: 
        { 
            0: { 
                sorter: false 
               }
        } 
    }
); 
});