yup, same here. I get this every time I try to log out from the user side (admin side seems to work fine).
Zend_Db_Statement_Mysqli->_execute() in Zend/Db/Statement.php at line 297
Zend_Db_Statement->execute() in Zend/Db/Adapter/Abstract.php at line 479
Zend_Db_Adapter_Abstract->query() in...