Setting 'debiti per ritenute da versare' as payable in order to handle it along with the due payments. See http://wiki.openerp-italia.org/doku.php/area_utente/requisiti/ritenuta_d_acconto#openerp bzr revid: lorenzo.battistini@agilebg.com-20120218133908-gh12l4d4vbw95fmd