When wp-e-commerce products are shown in an iframe, this will hopefully update the cart widget in the parent page

gistfile1.aw

// example of JavaScript for somewhere on the page
<script>
function myReloadCart() {
	form_values = "ajax=true&my_plugin_no_force_load=1"
	jQuery.post( 'index.php?wpsc_ajax_action=get_cart', form_values, function(returned_data) {
		eval(returned_data);
	});
}
</script>

<?php
// example of hook code for wpsc_alternate_cart_html action hook
function theme_cart_update() {
	$my_plugin_no_force_load = isset($_POST['my_plugin_no_force_load']) ? $_POST['my_plugin_no_force_load'] : 0;

	if ($my_plugin_no_force_load == 0)
		echo "if (window.parent) window.parent.myReloadCart();\n";
}
?>