Critical Description
The getBalance method sets up two entity condition lists; one for increases and one for decreases. The decrease list has a condition on the currencyUomId against the "FinAccountTransSum" view-entity. This entity does not have a currency (in fact currency is set on the financial acocunt itself, and not the transactions which must be in that currency. I have simply removed the offending line and cleaned up the method a little bit (generics violations, un-used variables).