Copy<config> <global> <helpers> <catalog> <rewrite> <data>Namespace_Module_Helper_Catalog_Data</data> </rewrite> </catalog> </helpers> </global> </config>
<config> <global> <helpers> <catalog> <rewrite> <data>Namespace_Module_Helper_Catalog_Data</data> </rewrite> </catalog> </helpers> </global> </config>