Error al procesar una retención del IVA

Al intentar procesar una retención del IVA en contabilidad->Withholding->Withholding Vat->Withholding Vat Customer y al introducir el partner, aparece el siguiente mensaje de error:

ERROR:db.cursor:Programming error: column res_partner.special does not exist
LINE 1: ...ve = E'True') AND (res_partner.ref = E'ide') AND (res_partne...
                                                             ^
, in query SELECT "res_partner".id FROM "res_partner" WHERE (res_partner.active = %s) AND (res_partner.ref = %s) AND (res_partner.special = 'True') AND (res_partner.customer = %s) ORDER BY name limit 100
ERROR:web-services:Uncaught exception
Traceback (most recent call last):
  File "/home/ralph/Proyectos/openerp/server/bin/osv/osv.py", line 122, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/ralph/Proyectos/openerp/server/bin/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/ralph/Proyectos/openerp/server/bin/osv/osv.py", line 167, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/ralph/Proyectos/openerp/server/bin/addons/base/res/partner/partner.py", line 196, in name_search
    ids = self.search(cr, uid, [('ref', '=', name)] + args, limit=limit, context=context)
  File "/home/ralph/Proyectos/openerp/server/bin/osv/orm.py", line 1743, in search
    return self._search(cr, user, args, offset=offset, limit=limit, order=order, context=context, count=count)
  File "/home/ralph/Proyectos/openerp/server/bin/osv/orm.py", line 4025, in _search
    cr.execute('SELECT "%s".id FROM ' % self._table + from_clause + where_str + order_by + limit_str + offset_str, where_clause_params)
  File "/home/ralph/Proyectos/openerp/server/bin/sql_db.py", line 78, in wrapper
    return f(self, *args, **kwargs)
  File "/home/ralph/Proyectos/openerp/server/bin/sql_db.py", line 131, in execute
    res = self._obj.execute(query, params)
ProgrammingError: column res_partner.special does not exist
LINE 1: ...ve = E'True') AND (res_partner.ref = E'ide') AND (res_partne...