I don't have this menu in a fresh 2.0 beta 4 installation onto which I restored a 2.0 beta 3.1 public database. I can approve deletion requests through the user's profile but the only way to reset the status is going into the database and changing the value of that one key (sorry, don't remember the name) from 4 to 1.
Any ideas?
Yes, go into sources/managemembers.php (I believe) and change "totalMembers" to "total_members". I had the same error :D.