=== modified file 'uc_taxes/uc_taxes.module'
--- uc_taxes/uc_taxes.module	2010-01-25 16:37:01 +0000
+++ uc_taxes/uc_taxes.module	2010-08-31 19:56:58 +0000
@@ -463,6 +463,24 @@
 function uc_taxes_javascript() {
   $order = $_POST['order'];
   if ($order = unserialize(rawurldecode($order))) {
+    // Alter the price of products prior to tax calculation.
+    foreach ((array) $order->products as $key => $value) {
+      $context = array(
+        'revision' => 'altered',
+        'type' => 'cart_item',
+        'subject' => array(
+          'cart_item' => $value,
+          'node' => node_load($value->nid),
+        ),
+      );
+      $price_info = array(
+        'price' => $value->price,
+        'qty' => $value->qty,
+      );
+
+      $order->products[$key]->price = uc_price($price_info, $context);
+    }
+
     $taxes = module_invoke_all('calculate_tax', $order);
     $callback = _line_item_data('tax_subtotal', 'callback');
     if (function_exists($callback)) {