Small fix in the online.php script:
Change this:
if ($Status == "User") { $Status = "<img src="{$config['images']}/blank.gif" alt="{$ubbt_lang['USER_MOD']}" border="0" />"; }
To this:
if ($Status == "User") { $Status = "<img src="{$config['images']}/blank.gif" alt="" border="0" />"; }
Otherwise there will be a tool tip saying "Moderator" if you happen to hover the pointer above the blank gif next to normal users.