--- shipping.module	2005-12-15 17:46:53.000000000 -0600
+++ shipping.module.patched	2006-03-24 09:55:40.078125000 -0600
@@ -329,12 +329,16 @@ function shipping_calculate($items) {
 
   if ($type == "subtotal") {
     foreach ($items as $item) {
-      $pivot_element += $item->qty * $item->price;
+      if (product_is_shippable($item->nid)) {
+        $pivot_element += $item->qty * $item->price;
+      }
     }
   }
   else {
     foreach ($items as $item) {
-      $pivot_element += $item->qty;
+      if (product_is_shippable($item->nid)) {
+        $pivot_element += $item->qty;
+      }
     }
   }