Impacted versions: 9.0, 9.0 enterprise

Steps to reproduce:
On current runbot duplicate any posted journal entry which is balanced

Current behavior:
Error message "Cannot create unbalanced entry" is shown

Expected behavior:
New Journal entry is created in state 'draft'

Video/Screenshot link (optional):
![selection_268](https://cloud.githubusercontent.com/assets/14974044/15007437/41f45a56-11d9-11e6-84f3-b297befaa521.png)

addons/account/models/account_move.py
import time
from openerp import api, fields, models, _
from openerp.osv import expression
from openerp.exceptions import RedirectWarning, UserError
from openerp.tools.misc import formatLang
from openerp.tools import float_compare, float_is_zero
from openerp.tools.safe_eval import safe_eval
from collections import OrderedDict
class AccountMove(models.Model):
    _name = "account.move"
    _description = "Account Entry"
    _order = 'date desc, id desc'
    @api.multi
    @api.depends('name', 'state')
    def name_get(self):
        result = []
        for move in self:
            if move.state == 'draft':
                name = '* ' + str(move.id)
            else:
                name = move.name
            result.append((move.id, name))
        return result
    @api.multi
    @api.depends('line_ids.debit', 'line_ids.credit')
    def _amount_compute(self):