Multi sortable connectWith placeholder wrong position

There are three small boxes connect with a big box. I can drag items in each small box to big box. I used jqueryui sortable.

The problem is when I drag item from small box into big box, the last item in big box will move down a space for the item that i was dragging, even i was dragging it at bottom of big box or below the position of last item in big box.

As expected, the item was be dragged which must be the last item in big box.

i used jquery-1.9.1.js, jquery-ui-1.10.3.custom.js in my example.

here is example from JsBin : http://jsbin.com/aMIxUHi/1/edit