Items not reflecting as overdue-FBL5N (AB document type)

Dear Experts,

The report Customer Line Item display FBL5N,The AB document type showing NOT DUE which automatically generated with amount difference in F-32.

The Billing document(RV) created and cleared with short payment received from customers Transaction code (F-32)and the new FI document created in AB document type in open item display in report FBL5N

For Example-
Billing document 1000 (RV)(Already due)

Payment received   RS 800.00
Cleared customers in F-32

RS 200.00 is open in FBL5N (AB document type)

Before it was showing OVERDUE in SAP 4.7 and now recently we completed upgradation ECC 6.0 EHP 6 however its showing not due for all customers those we have cleared with short payment.

Regards

Pulak