[dai-kun]

yeah, you can change it in the conquest.php file

$comment['avatarurl'] = $vbulletin->options['avatarurl'] . ($thumb ? '/thumbs' : '') . "/avatar{$comment['userID']}_{$comment['avatarrevision']}.gif";

But you should have thumbnails created for your custom avatars instead. Go to maintenace -> update counters -> Rebuild Custom Avatar Thumbnails
and it should work without any code edits.

Also if you notice that you have over 30 posts or however much you set your settings to be before pagination, the 2nd, 3rd and so on pages will show the same post no matter what. I don't know how to fix that.