I have some problem with the currency exchange, I don't know if is a bug or my error on some procedures, the point is the next:

I have a customer with following statement in the transaction inquiry:

Invoice    U$120
Payment  U$118
JE           U$-2    (an adjustment, i can't do credit note)
Total  =   U$ 0.00

BUT, when I make the revaluation currency account, it's always made me journal for this customer and it's balance is zero!

Researching and reviewing the function "get_cust_account_curr_balances" and trying to understand I reach that:

The journal entry in the debtor_trans is in negative so when the sql statement do the function sum 118 + (-2) = 116 minus the invoice, result 4 and this multiply by the currency exchange give me the amount that the system do in the exchange currency journal entry.

Actually, to resolve this I only made a Journal entry but I don't know if  this situation is correct.

Great Work ! Bless you