Why So many calls to USPS for now reason

Store Builder Questions
1

Hi,

In my logs I have many calls to: http://production.shippingapis.com/ShippingAPI.dll

Most end in errors: Missing value for ZipDestination.

  1. I don't have real time shipping methods active ( are some disabled) for domestic US shipping methods. I only have real time USPS for international shipping. US shipping methods are via table method. The default address just has United States for the country.
  2. For each item in that is added to the cart, multiple entries are in the logs to http://production.shippingapis.com/ShippingAPI.dll, all failures, until the person goes to final check out, then they add the zip code. But, this is not necessary for US destinations. I sometimes see 20 or more calls to USPS for one order.



    This seems like a waste of resources. Is this normal?



    Thanks,

    Bob