False "Bad total!" exception in account.invoice (trunk)

Hi!
Trunk version.
The situation: basic setup: a purchase invoice is made from a purchase order. There is one product with the price of 1.00 and a tax 0.18, resulting in a total of 1.18.
There is a problem in account_invoice.action_move_create() with the following lines (I have inserted debug()-s to show the problem):
for inv in self.browse(cr, uid, ids):
    debug('test1')
    debug(self.pool.get('account.invoice').read(cr, uid, inv.id, ['check_total']))
    self.button_compute(cr, uid, ids, context={},set_total=True)
    debug('test2')
    debug(self.pool.get('account.invoice').read(cr, uid, inv.id, ['check_total']))
    debug('test3 - variable not changed')
    debug(inv.check_total)
    if inv.type in ('in_invoice', 'in_refund') and abs(inv.check_total - inv.amount_total) >= (inv.currency_id.rounding/2.0):
        raise osv.except_osv(_('Bad total !'), _('Please verify the price of the invoice !\nThe real total does not match the computed total.'))

Log:
DEBUG:action_move_create:'test1'
DEBUG:action_move_create:self.pool.get('account.invoice').read(cr, uid, inv.id, ['check_total']) = {'check_total': 1.0, 'id': 1}
DEBUG:action_move_create:'test2'
DEBUG:action_move_create:self.pool.get('account.invoice').read(cr, uid, inv.id, ['check_total']) = {'check_total': 1.1799999999999999, 'id': 1}
DEBUG:action_move_create:'test3 - variable not changed'
DEBUG:action_move_create:inv.check_total = 1.0

The problem is that although account_invoice.button_compute() writes the new value to account_invoice.check_total, the variable inv in action_move_create() has the old incorrect value and the "Bad total!" exception is raised.