Ths part of the code in u-bp-forum-attachment.php :
if( $topic_template->current_post==0 ){
... should be replaced by this :
if($topic_template->posts[$topic_template->current_post]->post_position == 1) {
Explanation : current_post only gives the information about the position of the message in the order of the displayed list, which is not the same when a theme/plugin is made to show the newest post first.
http://wordpress.org/extend/plugins/u-buddypress-forum-attachment/
