Problem after upgrade ibProArcade

[nacaruncr]

Today after upgrade this hack, I had this error:

Database error in vBulletin 4.1.12:

Invalid SQL:

SELECT t.champion, u.userid FROM myweb_tournaments AS t
LEFT JOIN myweb_user AS u ON (t.champion = u.username)
WHERE champion<>'';

MySQL Error : Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (latin1_general_ci,IMPLICIT) for operation '='
Error Number : 1267
Request Date : Saturday, August 18th 2012 @ 04:06:09 AM
Error Date : Saturday, August 18th 2012 @ 04:06:10 AM
Script : http://www.myweb.com/showthread.php?t=3221
Referrer : http://www.myweb.com/showthread.php?t=3221
Username : username
Classname : vB_Database
MySQL Version : 5.5.24-cll

Somebody know how I can fix it, please?