Zend_Db_Registry::getInstance()->BlogAdapter = $db;
should be Zend_Db_Registry::getInstance()->blog = $db; //OR Zend_Db_Registry::getInstance()->blog = Zend_Db_Registry::DEFAULT;
Zend_Db_Registry::getInstance()->BlogAdapter = $db;
should be Zend_Db_Registry::getInstance()->blog = $db; //OR Zend_Db_Registry::getInstance()->blog = Zend_Db_Registry::DEFAULT;