hola amigos algunos de ustedes les ha salido algun error usando firefox3 y firebug sobre esto
[Exception... "'JavaScript component does not have a method named: "onRefreshAttempted"' when calling method: [nsIWebProgressListener2::onRefreshAttempted]" nsresult: "0x80570030 (NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED)" location: "<unknown>" data: no]