Receipt Accrual Period end process criteria?

Hi All,

We have situation here After Receipt Accrual Period End (MAr 12-13) and Create Acconting receiving as on 01-APR-2013 the following happened

1. two batches got created in March 12-13 period Actual and Encumberance

2. two Reverasal batches got created in APR-13-14 period Actual and Encumberance

But there is a differenec between Actual and Encumberance Totals, 

--> Found A PO whose receipt is corrected on 04-Apr-2013

--> For this PO only Actual journal entries are created and not Encumberance

Does Receipt Accrual does not recognise the Receipts correction which were done later than Accrual Period? And why it created Actuals but not encumberances.