Can't insert rows until table renamed?

[V@no .]

Hello.

Someone contacted me with an issue, when database doesn't accept any new rows. There is no error messages, it just mysql ignores INSERT command even when table is empty or deleted then recreated.
The strange thing is, when this same table renamed to different name, it accepts new rows. After adding few rows and then rename it to old name - same problem, no more new rows accepted...

Does anyone know what causing it and how to fix it?

Thanks.

DROP TABLE IF EXISTS `4images_wordlist`;
CREATE TABLE IF NOT EXISTS `4images_wordlist` (
`word_text` varchar(50) NOT NULL DEFAULT '',
`word_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`word_id`),
UNIQUE KEY `word_text` (`word_text`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1;