[horde] Empty window opening S/MIME signed messages

[Jānis]

Hi!

Somehow I lost ability to open S/MIME signed messages (no problems with PGP)

in PHP err log I see such msg (Horde 5.1.6/PHP 5.3.27):

PHP Fatal error:  Call to a member function isEmbedded() on a  
non-object in /X/horde5/imp/lib/Mime/Viewer/Smime.php on line 291,  
referer:  
https://Y/imp/basic.php?mailbox=SU5CT1guVGVobmlrYV91Yy5Ib3JkZQ&page=mailbox

it seems that opening of the message dies on certificate verification.

currently I have in config such line:
$conf['openssl']['cafile'] = '/usr/share/ca-certificates';

this directory holds sub-dirs with certificate bundles from cacert.org  
  mozilla  spi-inc.org. Even after ./update-ca-certificates nothing  
changes.

May be PHP is too old?

Janis