If any fields in the defined persona (tested with www.myopenid.com) is empty, for example excluding the emailadress in the persona, validation fails when Sreg properties want to be fetched. Problem can be found in Zend_OpenId_Extension_Sreg::parseResponse() of the class.

ORIGINAL CODE IN Zend_OpenId_Extension_Sreg::parseResponse(): foreach (self::getSregProperties() as $prop) { if (!empty($params['openid_sreg_' . $prop])) { $props[$prop] = $params['openid_sreg_' . $prop]; } }

MODIFIED TO WORK WITH NON EXISTENT PERSONA PROPERTIES: foreach (self::getSregProperties() as $prop) { if (isset($params['openid_sreg_' . $prop])) { $props[$prop] = $params['openid_sreg_' . $prop]; } else { $props[$prop] = ""; } }