Error in sortable (match is not a function)

Hello, I detect a bug with jquery sortable using jquery 1.7.2 and the update parameter

Example :

   $("ul#sortproduct").sortable({
	placeholder: 'ui-state-highlight',
        dropOnEmpty: false,
	axis: "y",
	cursor: "move",
	update : function (event, ui) {
	    var serial = $(this).sortable("serialize");
            //Ajax request ....
        }
   });

In Firebug :

TypeError: ($(o.item || this).attr(o.attribute || "id") || "").match is not a function

Probleme line 3698:

$(items).each(function() {
  var res = ($(o.item || this).attr(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));
  if(res) str.push((o.key || res[1]+'[]')+'='+(o.key && o.expression ? res[1] : res[2]));
});

Test Solution :

$(items).each(function() {
 var res = ($(o.item || this).prop(o.attribute || 'id') || '').match(o.expression || (/(.+)[-=_](.+)/));
 if(res) str.push((o.key || res[1]+'[]')+'='+(o.key && o.expression ? res[1] : res[2]));
});