--- uc_restrict_qty.module.orig	2010-02-28 06:48:37.000000000 +0000
+++ uc_restrict_qty.module	2010-02-28 06:49:18.000000000 +0000
@@ -281,7 +281,7 @@
 
   $data = db_fetch_array(db_query("SELECT qty, lifetime FROM {uc_restrict_qty_products} WHERE nid = %d", $form_values['nid']));
   if ($data['lifetime']) {
-    $bought_qty = db_result(db_query('SELECT SUM(uop.qty) FROM {uc_orders} uo LEFT JOIN {uc_order_products} uop ON uo.order_id = uop.order_id WHERE uo.order_status = "completed" AND uo.uid = %d AND uop.nid = %d ORDER BY uop.nid', $user->uid, $form_values['nid']));
+    $bought_qty = db_result(db_query('SELECT SUM(uop.qty) FROM {uc_orders} uo LEFT JOIN {uc_order_products} uop ON uo.order_id = uop.order_id WHERE uo.order_status = \'completed\' AND uo.uid = %d AND uop.nid = %d ORDER BY uop.nid', $user->uid, $form_values['nid']));
     $data['rest'] = $data['qty'] - $bought_qty;
   }