Shipping Rates not Changing in Shopping Cart if I change address

I have set up free shipping to US 48 per this link. Now that my demo store is set up, I am testing as a customer to make sure shipping, discounts, etc., working as expected. If I purchase an item from US 48 address, it shows free shipping, which is what I want. However, if I change the address while in shopping cart to international, it does not update the shipping info, it still lets me go to checkout with free shipping. However, if I place the order initially under international address, it does bring up shipping options/pricing. but if I change address in shopping cart to US 48, it still makes me pay shipping when I go to next step. Should it not recognize the address has changed and modify shipping? Not sure where I've mixed the wires, thank you.

What shipping method do you want to use for everyone other than the US 48?

USPS flat rate box or priority, our packaging, depending on product. To be honest, I do not know how to best fill out the shipping module options at the bottom where it lists all the choices. The shipping module I'm using in 1.39h doesn't have that many options, so maybe I have checked too many or too few. It does seem to recognize if US 48 or international and give either free shipping or USPS choices, however, only if I start the order that way, not if I change address during checkout to test.

For the Free Shipping for the US 48 are you marking all products as Always Free Shipping with Product Weight set for anything not in the US 48 or how are you doing the Free Shipping?

Yes, marking them as always free shipping with a product weight set. I will keep checking, maybe I missed something somewhere.

There are several steps to follow to allow Free Shipping for 1 Zone and everyone else gets charged ...

Edit the file:
/includes/classes/shipping.php

and add the code in RED:

  function calculate_boxes_weight_and_tare() {
    global $total_weight, $shipping_weight, $shipping_quoted, $shipping_num_boxes;

[B]// bof: allow 1 zone only for Always Free Shipping
// Always Free Shipping added back except for anyone in MODULE_SHIPPING_FREESHIPPER_ZONE
    global $db, $order, $cart;
        $valid_zone_id = MODULE_SHIPPING_FREESHIPPER_ZONE;
        $check_flag = false;
        $check = $db->Execute("select zone_id from " . TABLE_ZONES_TO_GEO_ZONES . " where geo_zone_id = '" . $valid_zone_id . "' and zone_country_id = '" . $order->delivery['country']['id'] . "' order by zone_id");
        while (!$check->EOF) {
          if ($check->fields['zone_id'] < 1) {
            $check_flag = true;
            break;
          } elseif ($check->fields['zone_id'] == $order->delivery['zone_id']) {
            $check_flag = true;
            break;
          }
          $check->MoveNext();
        }

        if ($check_flag == false) {
          $total_weight += $_SESSION['cart']->free_shipping_weight;
        }
// Always Free Shipping added back except for anyone in MODULE_SHIPPING_FREESHIPPER_ZONE
// eof: allow 1 zone only for Always Free Shipping
[/B]
    $this->abort_legacy_calculations = FALSE;

Edit the file:
/includes/modules/shipping/usps.php

and add the code in RED:

  function update_status() {
    global $order, $db;
    if (IS_ADMIN_FLAG == TRUE) return;

    // disable only when entire cart is free shipping
    if (zen_get_shipping_enabled($this->code) == FALSE) $this->enabled = FALSE;
[B]
// bof: allow 1 zone only for Always Free Shipping
// Always Free Shipping added back except for anyone in MODULE_SHIPPING_FREESHIPPER_ZONE
    if (!IS_ADMIN_FLAG) {
//echo 'I see quantity: ' . ($_SESSION['cart']->in_cart_check('product_is_always_free_shipping', 1)) . '<br>';
      $this->enabled = (MODULE_SHIPPING_USPS_STATUS == 'True') ? true : false;
      if ($this->enabled) {
        $valid_zone_id = MODULE_SHIPPING_FREESHIPPER_ZONE;
        $check_flag = false;
        $check = $db->Execute("select zone_id from " . TABLE_ZONES_TO_GEO_ZONES . " where geo_zone_id = '" . $valid_zone_id . "' and zone_country_id = '" . $order->delivery['country']['id'] . "' order by zone_id");
        while (!$check->EOF) {
          if ($check->fields['zone_id'] < 1) {
            $check_flag = true;
            break;
          } elseif ($check->fields['zone_id'] == $order->delivery['zone_id']) {
            $check_flag = true;
            break;
          }
          $check->MoveNext();
        }

        if ($check_flag == true) {
          if ($_SESSION['cart']->count_contents() == $_SESSION['cart']->in_cart_check('product_is_always_free_shipping', 1)) {
            $this->enabled = false;
          } else {
            $this->enabled = true;
          }
        } else {
          $this->enabled = true;
        }
      }
    }
// bof: allow 1 zone only for Always Free Shipping
// Always Free Shipping added back except for anyone in MODULE_SHIPPING_FREESHIPPER_ZONE
[/B]
    if ($this->enabled == true) {
      if ((int)MODULE_SHIPPING_USPS_ZONE > 0) {

Now set the Zone on the Modules ... Shipping ... FREE SHIPPING freeshipper to your US 48 shipping zone ...

What this should do is allow the Free Shipping to work for the US 48 and everyone else will be charged the weight from the Product Weight ...

See if this does it for you ...

Thank you. It is working now. However, I do have a question on the best way to set up shipping for those who are outside US 48 for them to have best choice of rates. I had selected some of the options in the USPS module. How do I know which ones to choose? For example, this is the choice that came up for me on a 34.00 order of 10 cassettes with Canada shipping address. I don't think there is a media mail any longer outside USA or a standard post, but the costs of shipping are quite hefty in my sample. I'm sure it is based on weight, and I think 4lbs is the priority mail limit for international. I may review my weights to make sure I'm not over-estimating, or talk to store owner about setting a flat rate on certain items for international shipping. Would that be possible, to just set a flat rate on non USA for SOME items, such as the smaller ones - cassettes, cards, etc.?

Thank you for your help.

United States Postal Service (1 Boxes) (5 lbs, 12 oz) $42.95
Priority Mail International® Medium Flat Rate Box (6 - 10 business days to many major markets)
$56.75
Priority Mail International® Large Flat Rate Box (6 - 10 business days to many major markets)

You could turn them all on and test a few orders to see what you want to offer to your customers ...

Then just use those settings for your shipping ...

Hadn't thought of that! Thank you for your help, I'll do that.

You should really check the weights ... a cassette tape weight is about 1.43 oz to 2.8 oz with/without the plastic case so 10 for 4 lbs sounds a bit high ...

Thank you. I'm revising weights, and have also checked out the different settings for choices and am working thru that. Shipping is working ok now, and am just tweaking the other weight/choices part of it.