PostgreSQL MAKE NO FIELD IN THE DATABASE

HOLA COMUNIDAD:

The following problem happens to me to want to keep a record in the database
data, and I was looking in postgres and I do not generate columns
x_placa, x_marca en la tabla modulo_autos:

Environment Information :
System : Windows-XP-5.1.2600-SP2
OS Name : nt
Operating System Release : XP
Operating System Version : 5.1.2600
Operating System Architecture : 32bit
Operating System Locale : es_CO.cp1252
Python Version : 2.5.2
OpenERP-Client Version : 5.0.10
Last revision No. & ID :Bazaar Package not Found !Traceback (most recent call last):
  File "netsvc.pyo", line 245, in dispatch
  File "netsvc.pyo", line 74, in __call__
  File "service\web_services.pyo", line 576, in execute
  File "osv\osv.pyo", line 58, in wrapper
  File "osv\osv.pyo", line 119, in execute
  File "osv\osv.pyo", line 111, in execute_cr
  File "osv\orm.pyo", line 2842, in create
  File "sql_db.pyo", line 77, in wrapper
  File "sql_db.pyo", line 122, in execute
ProgrammingError: column "x_modelo" of relation "modulo_autos" does not exist
LINE 1: insert into "modulo_autos" (id,"x_modelo","x_marca","x_placa...

This is the Python code:

from osv import osv, fields

class modulo_autos(osv.osv):
 _name = 'modulo.autos'
 _auto = 'False'
 _columns = {
  'x_placa': fields.char('PLACA', size=20),
  'x_marca': fields.char('MARCA', size=10),
  'x_modelo': fields.char('MODELO', size=10),
  }
modulo_autos()

CODE XML:

<terp>
<data>
<record model="ir.ui.view" id="view_modulo_autos_form">
<field name="name">modulo.autos.form</field>
<field name="model">modulo.autos</field>
<field name="type">form</field>
<field name="arch" type="xml">
<form string="modulo.autos">
 <!--<field name="assumpte" select="1">-->
 <field name="x_placa" required="1"/>
 <field name="x_marca"/>
 <field name="x_modelo"/>

<!--</field>-->
</form>
</field>
</record>

<record model="ir.ui.view" id="view_modulo_autos_tree">
<field name="name">vehiculos.tree</field>
<field name="model">modulo.autos</field>
<field name="type">tree</field>
<field name="arch" type="xml">
<tree string="modulo.autos">
<!--<field name="assumpte">-->
 <field name="x_placa" required="1"/>
 <field name="x_marca"/>
 <field name="x_modelo"/>

<!--</field>-->
</tree>

</field>
</record>

<record model="ir.actions.act_window" id="action_modulo_autos">
<field name="name">modulo.autos</field>
<field name="res_model">modulo.autos</field>
<field name="view_type">form</field>
<field name="view_mode">tree,form</field>

</record>

<menuitem name="GESTION VEHICULOS/Inventario/nuevo_auto"
id="menu_modulo_autos" action="action_modulo_autos"></menuitem>

</data>
</terp>

I can not find the solution to this problem thanks in advance
                                       ^