How to handle existing orders when activating ASN's for a customer?

When you are turning on ASN's for a customer (by setting up the hierarchical configuration information in the customer master), how do you handle any existing open orders for that customer?

Basically, we have existing orders for the customer and then go into the customer master and set up the hierarchical configuration for that customer. New orders will get the hierarchical configuration populated in the shipment header then when you subsequently run R47032 to generate ASN's the orders get picked up and the order status gets advanced.

The existing orders don't have the hierarchical configuration information and aren't getting processed by the R47032 and get stuck at a status waiting to have their ASN sent.