Images in thread bit (what's wrong?)

[Kanustep]

Hello,

I want to show in some foruns ids a thumbnail on threadbit. This is the code I'm being using that refers to this mod:
https://vborg.vbsupport.ru/showthread.php?t=158396

Threadbit template

<!-- Imagem Thumbnail -->
<if condition="$show['threadicons']">
    <td class="alt2" align="center" valign="middle">
            <if condition="$tt_displaythumbs">
                <if condition="($thread['attachmentid']) AND ($thread['thumbsize'])">
                     <a href="showthread.php?$session[sessionurl]t=$thread[threadid]">
                          <img src="attachment.php?attachmentid=$thread[attachmentid]&stc=1&thumb=1" alt="" border="0" />
                    </a>
                 <else />
                    <img src="$stylevar[imgdir_misc]/nothumb.gif" alt="" border="0" />
                 </if>
            <else />
                <if condition="$show['threadicon']">
                 <img src="$thread[threadiconpath]" alt="$thread[threadicontitle]" border="0" />
                 </if>
            </if>
    </td>
</if>
<!-- End of Imagem Thumbnail -->

Plug-in Code

PHP Code:

$tt_thumbsforums = array(57, 58, 59, 60, 61, 62, 63, 70);
$tt_displaythumbs = true;

if (in_array($forumid, $tt_thumbsforums)) {
    $tt_displaythumbs = true;
    $hook_query_fields .= ", attachment.thumbnail_filesize AS thumbsize , MIN(attachment.attachmentid) AS attachmentid ";
    $hook_query_joins .= "LEFT JOIN " . TABLE_PREFIX . "attachment as attachment ON(attachment.postid = thread.firstpostid AND (attachment.extension = 'jpg' OR attachment.extension = 'gif' OR attachment.extension = 'png')) ";
    $hook_query_where .= "GROUP BY thread.threadid ";
} 


It should work, but the problem is that show the thumbnails in all foruns, and don't strict to the ones I put in the array.