I would guess it's because $db is static.
Inspired by: http://www.yiiframework.com/wiki/123/multiple-database-support-in-yii/
I would try something like this, in your SynchroAR class.
... private $_currentDb = null; public function setDb($db = null) { if($db === null) { $this->_currentDb = null; parent::$db->setActive(true); } else { $this->_currentDb = $db; $this->_currentDb->setActive(true); } } public function getDbConnection() { if($this->_currentDb !== null) return $this->_currentDb; else return parent::$db; } protected function runSynchro($method) { $this->goSynchro = false; foreach($this->entryConns as $conn) { $this->setDb($conn); call_user_func(array($this, $method)); } $this->goSynchro = true; $this->setDb(); }