Configuration:
- Company Currency: MXN
- Tax 16%.
- Multicurrency, MXN and USD.
- Decimal precision: 4
- Currency Data:
MXN: rate 1.0
USD rates

| Database time | rate | Local time (Mexico) | 
| --- | --- | --- |
| 2016-09-09 00:00:01 | 0.054440 | 2016-09-08 17:00:01 |
| 2016-10-11 00:00:01 | 0.051815 | 2016-10-10 17:00:01 |

Steps to reproduce:

1. Create an invoice for 600 USD  + tax (16%) with date 09/09/16 (September 9, 2016) and when you validate in the journal entry is $12,784.7172 MXN.
3. Create a bank statement in MXN and add a line with date 11/10/16 (October 11, 2016) and amount $13,372.80 MXN.
4. When reconcile select the invoice and there is a difference ($588.0828 MXN) add a line with the difference and select an account for the difference. 
<img width="607" alt="captura de pantalla 2016-11-04 a la s 17 23 26" src="https://cloud.githubusercontent.com/assets/6758279/20025385/749605a2-a2b3-11e6-8b1a-4e9fbf1521ed.png">

**Note that the amount of difference is $588.08 in when you select the account**

5. Click on reconcile.

Expected behavior:
- Reconcile the invoice and create account move.

Current behavior:
- Raise an error  `Wrong credit or debit value in accounting entry !`

![captura de pantalla 2016-11-01 a la s 19 18 52](https://cloud.githubusercontent.com/assets/6758279/19913537/1c272866-a069-11e6-9b06-5851681c7fa5.png)

for line in self:
            if (line.amount_currency and not line.currency_id):
                raise UserError(_("You cannot create journal items with a secondary currency without filling both 'currency' and 'amount currency' field."))
    @api.multi
    @api.constrains('amount_currency')
    def _check_currency_amount(self):
        for line in self:
            if line.amount_currency:
                if (line.amount_currency > 0.0 and line.credit > 0.0) or (line.amount_currency < 0.0 and line.debit > 0.0):
                    raise UserError(_('The amount expressed in the secondary currency must be positive when account is debited and negative when account is credited.'))
    
    
    
    @api.model
    def get_data_for_manual_reconciliation_widget(self, partner_ids, account_ids):
        """ Returns the data required for the invoices & payments matching of partners/accounts.
            If an argument is None, fetch all related reconciliations. Use [] to fetch nothing.
        """
        return {
            'customers': self.get_data_for_manual_reconciliation('partner', partner_ids, 'receivable'),
            'suppliers': self.get_data_for_manual_reconciliation('partner', partner_ids, 'payable'),
            'accounts': self.get_data_for_manual_reconciliation('account', account_ids),
        }
    @api.model
    def get_data_for_manual_reconciliation(self, res_type, res_ids=None, account_type=None):