BuddyPress.org

OK, I took a quick look at BP 1.0.3 and it should work like this:

In bp-activity-classes.php add

$activities_formatted[$i]['user_id'] = $activities[$i]->user_id;

just as described above.

In bp-activity-widgets.php search for the line

<?php echo apply_filters( 'bp_get_activity_content', bp_activity_content_filter( $item['content'], $item['date_recorded'], '', true, false, true ) ); ?>

and change it to

<?php echo bp_core_get_avatar($item['user_id']) . apply_filters( 'bp_get_activity_content', bp_activity_content_filter( $item['content'], $item['date_recorded'], '', true, false, true ) ); ?>

You don’t need the other changes described in my previous posts, so just roll them back.