Thread:Extension talk:LDAP Authentication/Users authenticated by kerberos are not found in LDAP

I've set up apache to authenticate users by kerberos. Works. But: users are authenticated and granted access to the web server, but MediaWiki does not find the username within ldap. The only thing exausted are errors like:

[Fri Mar 25 16:09:42 2011] [error] [client 79.229.127.122] PHP Notice: Undefined offset: 1 in /opt/mediawiki/extensions/LdapAuthentication/LdapAuthentication.php on line 1527, referer: https://srv.example.com/wiki/index.php/Hilfe:Inhaltsverzeichnis

in line 1527 I found: $groups["short"][] = strtolower( $memAttrs[1] );

Further debugging gave: $memAttrs[1] is undefinde, because only $memAttrs[0] is set. We're working with an OpenLDAP server, not AD. Maybe we do not have an attribute AD delivers. Any idea where I could further look into it, making the whole thing work again?