--- app/code/core/Mage/Checkout/Model/Cart/Product/Api/V2.php.orig      2011-08-29 10:54:05.000000000 -0400
+++ app/code/core/Mage/Checkout/Model/Cart/Product/Api/V2.php   2011-10-07 16:24:57.000000000 -0400
@@ -58,18 +58,17 @@
                     $arr[$key] = $assocArr;
                 }
             }
-            $arr = $this->_prepareData($arr);
-            return parent::_prepareData($arr);
+            return $this->_prepareProductsData($arr);
         }
         if (is_array($data)) {
             foreach ($data as $key => $value) {
                 if (is_object($value) || is_array($value)) {
-                    $data[$key] = $this->_prepareData($value);
+                    $data[$key] = $this->_prepareProductsData($value);
                 } else {
                     $data[$key] = $value;
                 }
             }
-            return parent::_prepareData($data);
+            return $data;
         }
         return $data;