If a customer changes his address in his account, only the upcoming orders will have the new address.
Previously created orders (that have the "Future Shipment" status) still have the old address.
This has been a huge problem for us. Customers that subscribe for 6 months have 6 orders created at once, upon subscribing. Then whey go in their account to change their address and still receive 5 shipments to their old address. We have lost boxes and had to reship them because of this behavior.