Report Issue in OpenERP v7

I’m making a new report, from OpenOffice with base_report_designer module, on product object.

Everything seems ok, but everytime I try to print it, it throws this error:

Field 'product' does not exist in object 'browse_record(product.product, 12)'

(<type 'exceptions.AttributeError'>, AttributeError(KeyError("Field 'product' does not exist in object 'browse_record(product.product, 12)'",),), <traceback object at 0xc2801e4>)

This usually happens when you actually ‘save’ the document instead of sending to the server, but i’m not doing that, i’m using a parser made by me, using product.product model, and it should work, this is my parser:

import time
from openerp.report import report_sxw
class reporte_locacion(report_sxw.rml_parse):
def __init__(self, cr, uid, name, context):
    super(reporte_locacion, self).__init__(cr, uid, name, context=context)
    self.localcontext.update({
         'time': time,
         'qty_total':self._qty_total
    })

def _qty_total(self, objects):
    total = 0.0
    uom = objects[0].product_uom.name
    for obj in objects:
        total += obj.product_qty
    return {'quantity':total,'uom':uom}


report_sxw.report_sxw(
'report.reporte.locacion',
'product.product',
'addons/stock/report/reporte_locacion.rml',
parser=reporte_locacion,
header='internal'
)

And my report (sxw format, it has an .rml version):

[[ repeatIn(objects,'o') ]] 
Stock Inventory

Inventory
Date
[[ o.name ]]
[[ formatLang(o.date,date_time=True) ]]

Location
Production Lot
Product 
Quantity
[[ repeatIn(o.product, 'p') ]]
[[ p.location_id.name ]]
[[ p.prod_lot_id  and p.prod_lot_id.name or '' ]]
[ [[ p.product_id.code ]] ] [[ p.product_id.name ]]
[[ formatLang(p.product_qty) ]] [[ p.product_uom.name ]]

Total:
[[ formatLang(qty_total(o.inventory_line_id)['quantity']) ]] [[ qty_total(o.inventory_line_id)['uom'] ]]

Can’t figure it out, it should loop on product I don’t get it, any ideas?