jQuery.fn.fix_radios = function() {
  function focus() {
    // if this isn't checked then no option is yet selected. bail
    if ( !this.checked ) return;

    // if this wasn't already checked, manually fire a change event
    if ( !this.was_checked ) {
      jQuery( this ).change();
    }
  }

  function change( e ) {
    // shortcut if already checked to stop IE firing again
    if ( this.was_checked ) {
      e.stopImmediatePropagation();
      return;
    }

    // reset all the was_checked properties
    jQuery( "input[name=" + this.name + "]" ).each( function() {
      this.was_checked = this.checked;
    } );
  }

  // attach the handlers and return so chaining works
  return this.focus( focus ).change( change );
}

// attach it to all radios on document ready
jQuery(document).ready(function() {
  jQuery( "input[type=radio]" ).fix_radios();
} );