[TimberFloorAu]

UPDATE:

My original code is in fact correct.
Please revert postbit template changes, with this code below.

Open the postbit_legacy template

in Search In Template type :
$template_hook[postbit_signature_start]
$ad_location[ad_showthread_firstpost_sig]

After this add:

<!--YoBroMoFo Bellardia Thread Starter-->
<if condition="$post['signature'] OR $thread[postuserid] == $post[userid]">
<!-- sig -->
<div>
__________________<br />
<if condition="$thread[postuserid] == $post[userid]">
<img src="http://yourwebsite.com/forum/images/thread_starter.gif" alt="Thread Starter"><br />
</if>
$post[signature]
</div>
<!-- / sig -->
</if>
<!--end of YoBroMoFo Bellardia Thread Starter-->

************************************************** ***********************************************

Change http://yourwebsite.com/forum/images/thread_starter.gif to your filepath for the image
Upload the image to this destination using FTP
Change the alt="Thread Starter" above to your language translation or leave as is.

Please make special note to INCLUDE

$post[signature]

so that members signatures also appear.