[horde] ldap authentication with horde 2.2.5

[dju`]

Hello,

I'm trying to use a LDAP backend for authing users on horde. However, 
horde needs to bind with a specific "login" account before searching for 
username and password.

Here is my configuration:

$conf['auth']['driver'] = 'ldap';
$conf['auth']['params']['hostspec'] = 'ldap';
$conf['auth']['params']['port'] = '389';
$conf['auth']['params']['basedn'] = 'ou=users,dc=domain,dc=tld';
$conf['auth']['params']['uid'] = 'uid';
$conf['auth']['params']['username'] = 'uid=login,dc=domain,dc=tld';
$conf['auth']['params']['password'] = 'password';

Problem is, horde doesn't care about username and password settings, so 
it tries to search ldap anonymously, which returns no entry:

Aug 17 23:32:24 [slapd] conn=56 fd=10 ACCEPT from IP=192.168.0.254:36118 
(IP=0.0.0.0:389)_
Aug 17 23:32:24 [slapd] conn=56 op=0 SRCH 
base="ou=users,dc=domain,dc=tld" scope=2 filter="(uid=dju)"_
Aug 17 23:32:24 [slapd] conn=56 op=0 SRCH attr=uid_
Aug 17 23:32:24 [slapd] <= bdb_equality_candidates: (uid) index_param 
failed (18)_
Aug 17 23:32:24 [slapd] conn=56 op=0 SEARCH RESULT tag=101 err=0 
nentries=0 text=_
Aug 17 23:32:25 [slapd] conn=56 op=1 UNBIND_
Aug 17 23:32:25 [slapd] conn=56 fd=10 closed_

Any help would be appreciated, thanks.
-- 
--dju`