Zend_Db_Adapter_Pdo_Abstract::insert()
(Putting this here, mainly so that I can reference it!) There's a bug in Zend_Db_Adapter_Pdo_Abstract::insert(). I posted in to the mailing list and it's available here in the archives. In short, if you use the PDO drivers and have table field names with underscores in them, then you need to delete the insert() function within the class Zend_Db_Adapter_Pdo_Abstract.