Dunning Wizard

Hello

I'm experiencing a very annoying problem with the dunning wizard.

Customers where we have changed the payment terms have invoices that don't appear anymore in the dunning wizzard.

All the fiels where i can indicate to block dunning are left blank, so no blocking and still the field in INV6 DunWizBlck is set to Y ???

This means I can not trust the dunning wizard anymore.

How to correct?

This is a very urgent and important since I have to manually check all the clients in the dunning!