Import customer Fail. Prestashop 1.5.1, Openerp 6.1 with all related dependencies

[David]

I'm getting this error when I want to import customers from the main conector location

MERCATO-BIG: Start to import the ressource res.partner
2014-03-27 14:06:01,003 27035 INFO ? MERCATO-BIG: Created in OpenERP res.partner from External Ref withexternal_id 1 and OpenERP id 10 successfully
2014-03-27 14:06:01,393 27035 INFO ? MERCATO-BIG: Start to import the ressource res.partner.address
2014-03-27 14:06:01,674 27035 INFO ? MERCATO-BIG: Missing openerp resource for object res.country.state with external_id 340. Importing on the fly
2014-03-27 14:06:01,814 27035 ERROR ? openerp.sql_db: bad query: insert into "res_country_state" (id,create_uid,create_date) values (109,6,(now() at time zone 'UTC'))
Traceback (most recent call last):
  File "/opt/openerp-ocb/server_launch/openerp/sql_db.py", line 212, in execute
    res = self._obj.execute(query, params)
IntegrityError: null value in column "code" violates not-null constraint

2014-03-27 14:06:01,825 27035 ERROR test_prestashop openerp.netsvc: Integrity Error
The operation cannot be completed, probably due to the following:
- deletion: you may be trying to delete a record while other records still reference it
- creation/update: a mandatory field is not correctly set

[object with reference: code - code]

The customers have the state filled into the address in Prestashop