[turba] Turba and adressbook on DB Postgres and connexion not closed

[Philippe Grevet]

Hello,
My problem :
When i use the adressbook who is on Postgres (on a different server), the
connexion with the DB is'nt closed when i quit IMP, and I see with netstat
serveur DB Postgres :
=====================
tcp 0 0 watson.....in:postgres mendel.......f:2363 ESTABLISHED
Client webmail :
===============
tcp 0 0 mendel.....f:2363 watson:postgres ESTABLISHED

Installation :
RedHat 7.0
php-4.1.2-7.0.4
Pear-4.1.0
Horde-2.1
IMP-3.1
Turba-1.1

RedHat 7.0Authentification : pop3

Insertion, creation and deletion or import or export are ok
But there is only this problem of connexion not closed
And after a moment it's impossible to use the adressbook because there are too
much open connexion with the DB.
In horde.log this message :
sep 27 10:29:37 HORDE [emergency] [turba] Impossible de charger la 
d\351finition
de Turba_Driver_. [on line 44 of 
"/home/www/urgv/htdocs/webmail/horde/turba/lib
/Driver.php"]
I see the function close ()
in the /horde/turba/lib/Drivers/sql.php ....
And specific module in /usr/share/pear/DB/../pgsql.php
But i'm not an expert in php

Who can help me
Thanks