[imp] protocol error with openldap

[alois blasbichler]

hello list

i have a big problem with horde/imp
i have installed on a suse 8.1  horde2.1, imp3.1
with my users/passwords/preferences in LDAP : openldap 2.1.4-24

the authentication of the users with ldap works fine, turba works to,
but preferences and the passwd-module gives me an protocol error in ldap.php
i use : horde/lib/Prefs/ldap.php,v 1.14.2.10 2002/05/31

i have seen a lot of similar questions but no answers
is this a problem of  ldap.php  ??
i have read somthing about patches 
where can i get a newer version ??

please help  luis

the error in horde.log:
------------------------------------------
Nov 06 15:04:21 HORDE [info] [imp] Bind to server mir:389 with DN 
uid=test2,dc=sb-brixen,dc=it failed: [2] Protocol error [on line 169 
of "/srv/www/htdocs/horde/lib/Prefs/ldap.php"]