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)

addons/account/models/account_move.py
self._update_check()
        move_ids = set()
        for line in self:
            if line.move_id.id not in move_ids:
                move_ids.add(line.move_id.id)
        result = super(AccountMoveLine, self).unlink()
        if self._context.get('check_move_validity', True) and move_ids:
            self.env['account.move'].browse(list(move_ids))._post_validate()
        return result
    @api.multi
    def write(self, vals):
        if ('account_id' in vals) and self.env['account.account'].browse(vals['account_id']).deprecated:
            raise UserError(_('You cannot use deprecated account.'))
        if any(key in vals for key in ('account_id', 'journal_id', 'date', 'move_id', 'debit', 'credit')):
            self._update_check()
        if not self._context.get('allow_amount_currency') and any(key in vals for key in ('amount_currency', 'currency_id')):
            
            
            self._update_check()
        
        if vals.get('expected_pay_date') and self.invoice_id:
            msg = _('New expected payment date: ') + vals['expected_pay_date'] + '.\n' + vals.get('internal_note', '')
            self.invoice_id.message_post(body=msg) 
        
        for record in self:
            if 'statement_id' in vals and record.payment_id: