Vendor Master not assigned to 000 Model in APO automatically

We have ciffed a Vendor master using "Send as Location" option as we dont have Business Partners created for vendors in our system. After ciffing the vendor master the data is available in APO and assigned to version 000 automatically but when we look at the Model assignment tab in LOC3 transaction it has not checked the green tick mark and we had to assign the model automatically. Can gurus help on this or may be a similar issue you guys have seen in your past experience would be appreciated.