--- /tmp/ldap_integration/ldap_integration/LDAPInterface.php    2008-07-21 23:19:38.000000000 +0200
+++ LDAPInterface.php   2008-09-09 22:42:20.018142236 +0200
@@ -235,7 +235,9 @@
       if ($cur_val == '') {
         unset($attributes[$key]);
         $old_value = $this->retrieveAttribute($dn, $key);
-        ldap_mod_del($this->connection, $dn, array($key => $old_value));
+        if ($old_value) {
+          ldap_mod_del($this->connection, $dn, array($key => $old_value));
+        }
       }
       if (is_array ($cur_val)) {
         foreach ($cur_val as $mv_key => $mv_cur_val) {