Correction rapide, pour bien avoir toutes les régions

app/controllers/events_controller.rb

@@ -89,7 +89,7 @@ class EventsController < ApplicationController
   def set_events
     @events = Event.moderated
     @events = @events.region params[:region] \
-      if params[:region].present? && params[:region] != 'all'
+      if params[:region] && params[:region] != 'all'
     @events = @events.tag(params[:tag]) if params[:tag]
   end
 

app/views/regions/_selector.haml

@@ -1,7 +1,7 @@
 %nav.region_selector
   -# Display the currently selected region
   %h3
-    - if params[:region]
+    - if params[:region] && params[:region] != 'all'
       = Region.find params[:region]
       %em.fa.fa-chevron-down
     - else