New Thread not functionally - DB Error - Urgent

[mondoforum.org]

Hi to all, excuse me for my bad english but I am italian. I have upgrade tu vbulletin 3.8 Beta 4 but when I click on button new thread I have this error:

Database error in vBulletin 3.8.0 Beta 4:

Invalid SQL:

            SELECT prefix.*, prefixpermission.usergroupid AS restriction
            FROM vb_forumprefixset AS forumprefixset
            INNER JOIN vb_prefixset AS prefixset ON (prefixset.prefixsetid = forumprefixset.prefixsetid)
            INNER JOIN vb_prefix AS prefix ON (prefix.prefixsetid = prefixset.prefixsetid)
            LEFT JOIN vb_prefixpermission AS prefixpermission ON (prefix.prefixid = prefixpermission.prefixid)
            WHERE forumprefixset.forumid = 23
            ORDER BY prefixset.displayorder, prefix.displayorder;

MySQL Error   : Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '='
Error Number  : 1267
Request Date  : Tuesday, December 2nd 2008 @ 10:36:51 AM
Error Date    : Tuesday, December 2nd 2008 @ 10:36:52 AM
Script        : http://www.pchs.it/forums/newthread.php?do=newthread&f=23
Referrer      : http://www.pchs.it/forums/22-software/23-sistemi-operativi/
IP Address    : 82.57.110.181
Username      : pchs
Classname     : vB_Database
MySQL Version : 5.0.51a-community

Please help me.. is urgent...

[Hatsu]

Use phpmyadmin to switch the collation of the affected tables.

The collation is showed on the overview page showing the tables. So switch utf8_general_ci to utf8_unicode_ci or vice versa depending which collation is standard in your database.

[mondoforum.org]

I switch utf8_unicode_ci in utf8_general_ci but the problem persist...

[Hatsu]

You must change the tables by hand. Existing tables aren't changed with that.

[mondoforum.org]

Ok.. I changed the single table and now functionally.. thanks...