3.7.5 forumumu 3.8.1 de yükseltmek için upgrade yaptım lakin böyle bir hata verdi son adımda

bu aşamada
Step 5) Upgrade to vBulletin 3.8.0 Alpha 2 Complete! (Step 5 of 5)

Database error in vBulletin 3.7.5:

Invalid SQL:

        SELECT prefix.*, prefixpermission.usergroupid AS restriction
        FROM prefix AS prefix
        LEFT JOIN prefixpermission AS prefixpermission ON (prefix.prefixid = prefixpermission.prefixid)
        ORDER BY prefix.displayorder;

MySQL Error   : Illegal mix of collations (latin1_general_ci,IMPLICIT) and (latin1_swedish_ci,IMPLICIT) for operation '='
Error Number  : 1267
Request Date  : Saturday, March 14th 2009 @ 05:27:26 PM
Error Date    : Saturday, March 14th 2009 @ 05:27:26 PM
Script        : http://www.yuppiforum.com/install/upgrade_380a2.php?step=5
Referrer      : http://www.yuppiforum.com/install/upgrade_380a2.php?step=4
IP Address    : 78.184.174.17
Username      : 
Classname     : vB_Database
MySQL Version : 5.0.67-community

neden olmuş olabilir bu =? yardımlarınızı bekliyorum