Safari doesn't display the lock icon on that site either ... However it seems that it is a CACert signed certificate, so you may download the root certificates

Safari doesn't display the lock icon on that site either ... However it seems that it is a CACert signed certificate, so you may download the root certificates and add them to your browser/OS from here: http://www.cacert.org/index.php?id=3 http://www.cacert.org/index.php?id=3