My Base Currency is USD. I have a customer invoice at 01.01.2014 with 1000 EUR. at that time rate was 1.3. Now at 01.01.2015 my customer paid the invoice in USD  with amount of 1100 USD as the rate is 1.1.When i register a customer payment  system can't calculate the exchange rate loss automatically, as EUR invoice was paid in USD. It should have recorded like this:

Invoide: Paid

Debit: Bank1100

Debit: Loss: 200

Credit: Account Receivable:1300. 

Customer Balance= 0

Instead of that system did this:

Debit: Bank 1300

Credit: Debtor 1100

Credit: Debtor 200

Customer Balance= -200.

Anyone has any idea?