Moderators Problem

[lovebeer]

Hi, I have a problem.
My mod's can't promote, can't give warn, can't give disable, can't do nothing there...
They give warn or promote, but after they press "Okay" this error appears:

SQL Error

 Duplicate entry '' for key 2in  /home/tracker_name/domains/tracker_domain/public_html/modtask.php, line 152

This is line 152 from modtask:

 mysql_query("UPDATE users SET " . implode (",  ", $updateset ) . "WHERE id=".sqlesc($userid)) or sqlerr(__FILE__, __LINE__);

Please help me, I really need help with this!