--- /Users/matt/Downloads/ubercart/uc_attribute/uc_attribute.module
+++ uc_attribute.module
@@ -371,6 +371,7 @@
       $combination[$aid] = $value;
     }
   }
+	ksort($combination);
   $result = db_query("SELECT model FROM {uc_product_adjustments} WHERE nid = %d AND combination LIKE '%s'", $form_values['nid'], serialize($combination));
   $model = db_result($result);
   // drupal_set_message('Attributes to add to order Array(aid => oid):<pre>'. print_r($form_state['values']['attributes'], TRUE) . $model .'</pre>');