BuddyPress.org

In bp-activity-classes.php try to add this line of code to the get_activity_for_user() function (There are a couple of very similar code lines, just add it after those)

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

Also I just recognized that the hackdescribed in this thread won’t work in BP 1.0.3 as there were some core changes.