[LeeCHeSSS]

Ok, how to hide the quick reply box when a user is reply-banned:

In showthread.php find:

if (($bbuserinfo['userid']!=$thread['postuserid']) and (!$getperms['canviewothers'] or !$getperms['canreplyothers'])) {

Right BEFORE that, INSERT:

$threadban=$DB_site->query_first("SELECT COUNT(DISTINCT banid) AS activeban
                                  FROM bans
                                  WHERE userid=$bbuserinfo[userid] AND threadid=$threadid AND active=1
                                 ");

Next, find:

} else {
        $textareacols = gettextareawidth();
        eval("\$replybox = \"".gettemplate('showthread_replybox')."\";");
}

and right BEFORE that, INSERT:

} elseif ($threadban[activeban]!=0) {
        $replybox='';

That's it. And for the query freaks: yes it DOES add a query.