Tryng to update MySQL from 5.0.27 to 5.1.41, getting ERROR 1062 on table 'word'

[محروم.كوم]

I dumped my old VB with mysqldump, trying to restore on a new machine. It fails with this error:

ERROR 1062 (23000) at line 21: Duplicate entry 'wei?' for key 'title'

I've narrowed it down to the following small case:

Code:
--
-- Table structure for table `word`

--

set names utf8;

DROP TABLE IF EXISTS `word`;
CREATE TABLE `word`
(
`wordid` int (10) unsigned NOT NULL auto_increment,
`title` char (50) NOT NULL default '',
PRIMARY KEY (`wordid`),
UNIQUE KEY `title` (`title`)
) ENGINE=MyISAM AUTO_INCREMENT=280707 DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci;

--
-- Dumping data for table `word`
--

LOCK TABLES `word` WRITE;
INSERT INTO `word` VALUES
(198036,'weis'),
(241473,'wei?');
UNLOCK TABLES;
I've looked at all my collations, and they are identical between the versions. Even if they weren't the CHARSET is specified for this table.

Any clues? __DEFINE_LIKE_SHARE__