Transaction in different curency


In Account Statement Report, for an account in which are registered the expenses from currency difference, I find vouchers which seems to be automatic generated in AX 2009 when a payment is done in a currency which is different from the payed invoice currency. The problem is that the amount from this voucher is too big to represent that. I don’t know why and how i can check what this voucher represent and how i can correct it. Please can anyone help me?

Any help will be very very much appreciated.