IE7 stops anti-aliasing when sorting stops if revert=false and opacity is used

When revert=false (i.e. no animation of the moved element at the end of the sorting) the filter style isn't cleared and IE stops anti-aliasing the content of the element that was moved.

Filter style is cleared properly when revert=true.

As a fix I have to use this code for the ui.sortable stop event:

stop: function(event, ui) {
  if (!jQuery.support.opacity) {
    ui.item.each(function() {
      this.style.removeAttribute('filter');
    });
  }
}