Before adding this MOD to your forum, you should back up all files and databases related to this MOD.
This MOD was designed for Avatar of poster on Index and Viewforum 1.3.0 / Board3 2.0.1
 and may not function as stated on other Avatar of poster on Index and Viewforum / Board3 versions.
EDIT: I updated the first edit
Open: portal/includes/functions.php
Find
Tip: This may be a partial find and not the whole line.
Add after
Code: Select all
            t.topic_first_poster_avatar,
            t.topic_last_poster_avatar,
Code: Select all
            'attachments'            => (!empty($attachments)) ? $attachments : array(),
Code: Select all
//-- mod : apiv ----------------------------------------------------------------
//-- add
//-- Board3
            'topic_first_poster_avatar'            => $row['topic_first_poster_avatar'],
            'topic_last_poster_avatar'            => $row['topic_last_poster_avatar'],
//-- fin mod : apiv ------------------------------------------------------------                   
Code: Select all
                    
                    // Grab icons
                    $icons = $cache->obtain_icons();
Code: Select all
//-- mod : apiv ----------------------------------------------------------------
//-- add
//-- Board3
                    if ( $config['avatar_topics_first_poster_show'] || $config['avatar_topics_last_poster_show'] )
                    {
                        $template->assign_var('AVATAR_MAX_DIMENSIONS', $config['avatar_max_dimensions']);
                    }
//-- fin mod : apiv ------------------------------------------------------------                    
Code: Select all
                    if(!empty($fetch_news[$i]['attachments']))
                    {
                        foreach ($fetch_news[$i]['attachments'] as $attachment)
                        {
                            $template->assign_block_vars('news_row.attachment', array(
                                'DISPLAY_ATTACHMENT'    => $attachment)
                            );
                        }
                    }
Code: Select all
//-- mod : apiv ----------------------------------------------------------------
//-- add
//-- Board3
                    user_display_avatar($fetch_news[$i], 'topic_first', 'news_row', $config['avatar_topics_first_poster_show']);
                    user_display_avatar($fetch_news[$i], 'topic_last', 'news_row', $config['avatar_topics_last_poster_show']);
//-- fin mod : apiv ------------------------------------------------------------                    
Code: Select all
<!-- IF news_row.S_UNREAD_TOPIC -->
Code: Select all
<!-- IF news_row.TOPIC_FIRST_POSTER_AVATAR --><span style="float: left; padding-top: 3px; margin-right: {news_row.TOPIC_FIRST_POSTER_AVATAR_MARGIN}px;">{news_row.TOPIC_FIRST_POSTER_AVATAR}</span><!-- ENDIF -->
Code: Select all
<span><dfn>{L_LAST_POST}</dfn>{L_POST_BY_AUTHOR} {news_row.USERNAME_FULL_LAST} <!-- IF news_row.S_UNREAD_INFO --><a href="{news_row.U_VIEW_UNREAD}">{NEWEST_POST_IMG}</a><!-- ELSE --><a href="{news_row.U_LAST_COMMENTS}">{READ_POST_IMG}</a><!-- ENDIF --><br />
				{news_row.LAST_POST_TIME}</span>
Code: Select all
<!-- IF news_row.TOPIC_LAST_POSTER_AVATAR --><div style="float: left; padding-top: 0px; margin-left: 5px; margin-right: {news_row.TOPIC_LAST_POSTER_AVATAR_MARGIN}px;">{news_row.TOPIC_LAST_POSTER_AVATAR}</div><!-- ENDIF -->
Enjoy
A picture:
 
You can find a MODX Version of this mod 
here (subsilver2 included, Automod ready)