"Payment Status" in Payables Trial Balance Report

Hi, 

Just to ask about the standard report "Payables Trial Balance Report" parameter is in "detail" and as of July 31, 2011.

I just noticed the output is correct as to total amount of TB but just to ask about "Payment Status" the invoices status is "Fully Paid' as seen in TB. 

The invoiced is paid in the month of August2011, but the parameter in running Payables Trial Balance is July 31, 2011

Is ths the normal behaviour even i run the report as of July 31, 2011 and the payment was made in August but the status of the invoices is updated

as seen in the Payables Trial Balance as of July 31, 2011.