Flag Friend trigger no respond

i try to assign an action to the flag_friend_approve and flag_friend_request triggers, but nothing happens.

function flag_friend_flag_friend($op, $friend, $user)
seems not working properly.

i try to change the second two lines in this function like this:

//  if (function_exists('_trigger_get_hook_aids')) {
//    $aids = _trigger_get_hook_aids('flag_friend', $op);
  if (function_exists('trigger_get_assigned_actions')) {
    $aids = trigger_get_assigned_actions('flag_friend_' . $op);

and then it works.
please check this function again.
thanks.