I discovered an issue with 3.0.0 installed on 1.5.7b. If the shipping estimator is configured to display a button that opens the popup, the dropdowns incorrectly display the last states after the country is changed. I found that the template in includes/templates/bootstrap/templates/tpl_modules_shipping_estimator.php was missing the onchange.
I changed line 59 from
PHP Code:
<?php echo zen_get_country_list('zone_country_id', $selected_country, 'id="country"'); ?>
To
PHP Code:
<?php echo zen_get_country_list('zone_country_id', $selected_country, 'id="country" onchange="update_zone(this.form);"'); ?>
This fixes the issue