Doctrine inserting error - Table CATEGORIES

CREATE TABLE `categories` (
 `id` smallint(6) NOT NULL AUTO_INCREMENT,
 `languages_id` int(11) NOT NULL,
 `parent_id` smallint(6) NOT NULL,
 `title` varchar(255) NOT NULL,
 PRIMARY KEY (`id`),
 KEY `languages_id` (`languages_id`),
 CONSTRAINT `categories_ibfk_1` FOREIGN KEY (`languages_id`) REFERENCES `languages` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8