'Append page title to breadcrumb' not working for forum module pages

I just noticed this on my website as well. A fix would really be appreciated.

I believe this is due to forum_node_view setting the breadcrumb. You could probably just implement hook_node_view or override template_preprocess_page to get the breadcrumb and append the title. For appending see, this bit from menu_breadcrumb_init:

  if (variable_get('menu_breadcrumb_append_node_title', 0) == 1) {
    $node_title = filter_xss(menu_get_active_title(), array());
    if (variable_get('menu_breadcrumb_append_node_url', 0) == 1) {
      $breadcrumb[] = $is_front ? l(t('Home'), '<front>') : l($node_title, $_GET['q'], array('html' => TRUE,));
    }
  ...