menu_navigation_links() active-trail

I have a problem with menu_navigation_links function. It seems to me that active-trail class is not added.

tested with page.tp.php

$menu = menu_navigation_links('navigation', 2);
print theme('links', $menu, array('id' => 'mymenu'));

type url: admin/content/types/add
the "Content types" menu item should have "active-trail" class added, but it has not..