zc 1.3.9g using EC.
Paypal put some transactions on hold while they did a fraud investigation. This came through OK (IPN report shows transaction, order comments added, order status changed to Pending).

When paypal resolved the issue, they cancelled the reversal and released the funds. An IPN transaction came in with payment_gross containing the funds, payment_status=Canceled_Reversal. IPN report (Customers->PaypalIPN) shows the IPN, but the order still says payment status=Denied, with no comments added to the order.

Transaction generated lines in paypal, paypal_payment_status_history, but not orders_status_history.

How can I get these IPN transactions to accurately update the order?