def check_vies(vat): is no longer working due to changes in the SOAP service.

As described here: http://ec.europa.eu/taxation_customs/vies/checkVatService.wsdl

urn:ec.europa.eu:taxud:vies:services:checkVat:types

As observed in OpenERP

client.service is part of suds not the API of ec.europa.eu For me, the current implementation still works even if the server responds BUSY.