attempt to fix a bad bug??

app/models/ticket_purchase.rb

@@ -105,6 +105,8 @@ def set_week
 end
 
 def count_purchased_registration_tickets(conference, purchases)
+  # TODO: WHAT CAUSED THIS???
+  return unless purcahses
   conference.tickets.for_registration.inject(0) do |sum, registration_ticket|
     sum + purchases[registration_ticket.id.to_s].to_i
   end