Opening amount is shown in report as income

Financial 1.4.2

Steps to reproduce:
1. Create new account with some opening account
2. Add several transactions
3. Open "Transactions by period" report

Actual result:
Opening amount is counted as income.

Expected result:
I think that the primary role of this report is to view income/expense ratio for some period. In this sense showing opening amount isn't correct, because those money were earned for some (probably long) period before reported one.