diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 4cc79f7..21ba92d 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -24,7 +24,7 @@ require 'authentication.rb'
 
 class ApplicationController < ActionController::Base
   helper :all
-  # protect_from_forgery
+  protect_from_forgery
 
   include AuthenticationSystem
 
@@ -59,7 +59,8 @@ class ApplicationController < ActionController::Base
     end
   end
 
-  def show_not_found
+  def show_not_found(exception)
+    fail Exception if Rails.env.production?
     respond_to do |format|
       format.html { render file: "#{Rails.root}/public/404.html", status: 404, layout: false }
       format.xml { head 404 }
diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index fce83a8..7a657ef 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -20,103 +20,93 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 class AttachmentsController < ApplicationController
-
-	#verify :method => :post, :only => [ :destroy, :create, :update ],
-	#	:redirect_to => { :controller => 'courses', :action => :show }
-
-	#after_filter :cache_sweep, :only => [ :create, :update, :destroy ]
-
-	before_filter :find_attachment
-
-	def show
-		respond_to do |format|
-			format.html
-			format.xml { render :xml => @attachment }
-		end
-	end
-
-	def new
-	end
-
-	def create
-		@attachment.course_id = @course.id
-		@attachment.path = params[:attachment][:path]
-		@attachment.front_page = params[:attachment][:front_page]
-		@attachment.description = params[:attachment][:description]
-		@attachment.file_name = "blank"
-		unless params[:attachment][:file].nil?
-			@attachment.file = params[:attachment][:file]
-			@attachment.file_name = params[:attachment][:file].original_filename
-			@attachment.content_type = params[:attachment][:file].content_type
-		end
-		@attachment.save!
-
-		AttachmentCreateLogEntry.create!(:target_id => @attachment.id, :user => @current_user, :course => @course)
-		flash[:notice] = t(:attachment_created)
-
-		respond_to do |format|
-			format.html { redirect_to course_attachment_url(@course, @attachment) }
-			format.xml { head :created, :location => course_attachment_url(@course, @attachment, :format => :xml) }
-		end
-	end
-
-	def edit
-	end
-
-	def update
-		@attachment.path = params[:attachment][:path]
-		@attachment.front_page = params[:attachment][:front_page]
-		@attachment.description = params[:attachment][:description]
-		unless params[:attachment][:file].nil?
-			@attachment.file = params[:attachment][:file]
-			@attachment.file_name = params[:attachment][:file].original_filename
-			@attachment.content_type = params[:attachment][:file].content_type
-		end
-		changed = @attachment.changed?
-
-		if changed
-			@attachment.last_modified = Time.now.utc
-			@attachment.save!
-			AttachmentEditLogEntry.create!(:target_id => @attachment.id, :user => @current_user, :course => @course)
-			flash[:notice] = t(:attachment_updated)
-		end
-
-		respond_to do |format|
-			format.html { redirect_to course_attachment_url(@course, @attachment) }
-			format.xml { head :created, :location => course_attachment_url(@course, @attachment, :format => :xml) }
-		end
-	end
-
-	def destroy
-		@attachment.destroy
-		flash[:notice] = t(:attachment_removed)
-
-		log = AttachmentDeleteLogEntry.create!(:target_id => @attachment.id, :user => @current_user, :course => @course)
-		flash[:undo] = undo_course_log_url(@course, log)
-
-		respond_to do |format|
-			format.html { redirect_to course_url(@course) }
-			format.xml { head :ok }
-		end
-	end
-
-	def download
-
-		send_file("#{Rails.root}/public/upload/#{@course.id}/#{@attachment.id}",
-				:filename    =>  @attachment.file_name,
-				:type        =>  @attachment.content_type,
-				:disposition =>  'inline',
-				:streaming   =>  'true')
-	end
-
-	protected
-	def find_attachment
-		params[:course_id] = Course.find(:first, :conditions => ['short_name = ?', params[:course_id]], :order => 'period desc').id if !params[:course_id].is_numeric? and !Course.find_by_short_name(params[:course_id]).nil?
-		@course = Course.find(params[:course_id])
-		@attachment = params[:id] ? @course.attachments.find(params[:id]) : Attachment.new
-	end
-
-	def cache_sweep
-		expire_fragment(course_path(@course.id))
-	end
+  before_filter :find_attachment
+  
+  def show
+    respond_to do |format|
+      format.html
+      format.xml { render xml: @attachment }
+    end
+  end
+
+  def new
+  end
+
+  def create
+    @attachment.course_id = @course.id
+    @attachment.path = params[:attachment][:path]
+    @attachment.front_page = params[:attachment][:front_page]
+    @attachment.description = params[:attachment][:description]
+    @attachment.file_name = "blank"
+    unless params[:attachment][:file].nil?
+      @attachment.file = params[:attachment][:file]
+      @attachment.file_name = params[:attachment][:file].original_filename
+      @attachment.content_type = params[:attachment][:file].content_type
+    end
+    @attachment.save!
+
+    AttachmentCreateLogEntry.create!(target_id: @attachment.id, user: @current_user, course: @course)
+    flash[:notice] = t(:attachment_created)
+
+    respond_to do |format|
+      format.html { redirect_to course_attachment_url(@course, @attachment) }
+      format.xml { head :created, location: course_attachment_url(@course, @attachment, format: :xml) }
+    end
+  end
+
+  def edit
+  end
+
+  def update
+    @attachment.path = params[:attachment][:path]
+    @attachment.front_page = params[:attachment][:front_page]
+    @attachment.description = params[:attachment][:description]
+    unless params[:attachment][:file].nil?
+      @attachment.file = params[:attachment][:file]
+      @attachment.file_name = params[:attachment][:file].original_filename
+      @attachment.content_type = params[:attachment][:file].content_type
+    end
+    changed = @attachment.changed?
+
+    if changed
+      @attachment.last_modified = Time.now.utc
+      @attachment.save!
+      AttachmentEditLogEntry.create!(target_id: @attachment.id, user: @current_user, course: @course)
+      flash[:notice] = t(:attachment_updated)
+    end
+
+    respond_to do |format|
+      format.html { redirect_to course_attachment_url(@course, @attachment) }
+      format.xml { head :created, location: course_attachment_url(@course, @attachment, format: :xml) }
+    end
+  end
+
+  def destroy
+    @attachment.destroy
+    flash[:notice] = t(:attachment_removed)
+
+    log = AttachmentDeleteLogEntry.create!(target_id: @attachment.id, user: @current_user, course: @course)
+    flash[:undo] = undo_course_log_url(@course, log)
+
+    respond_to do |format|
+      format.html { redirect_to course_url(@course) }
+      format.xml { head :ok }
+    end
+  end
+
+  def download
+    send_file("#{Rails.root}/public/upload/#{@course.id}/#{@attachment.id}",
+              filename: @attachment.file_name,
+              type: @attachment.content_type,
+              disposition: 'inline',
+              streaming: 'true')
+  end
+
+  protected
+
+  def find_attachment
+    params[:course_id] = Course.find(:first, conditions: ['short_name = ?', params[:course_id]], order: 'period desc').id if !params[:course_id].is_numeric? && !Course.find_by_short_name(params[:course_id]).nil?
+    @course = Course.find(params[:course_id])
+    @attachment = params[:id] ? @course.attachments.find(params[:id]) : Attachment.new
+  end
 end
diff --git a/app/controllers/courses_controller.rb b/app/controllers/courses_controller.rb
index 50a4605..e4704ca 100644
--- a/app/controllers/courses_controller.rb
+++ b/app/controllers/courses_controller.rb
@@ -24,11 +24,9 @@ class CoursesController < ApplicationController
                                        :destroy]
   before_filter :require_login, only: [:enroll, :unenroll]
   before_filter :find_course, except: [:index]
-  # after_filter :cache_sweep, only: [ :create, :update, :destroy ]
 
   def index
-    @period = params[:period] || App.current_period
-    @courses = Course.visible.where(period: @period)
+    @period = params[:period].blank? ? App.current_period : params[:period]
 
     respond_to do |format|
       format.html
@@ -115,10 +113,4 @@ class CoursesController < ApplicationController
   def require_admin
     fail AccessDenied, 'only admins can modify courses' unless admin?
   end
-
-  def cache_sweep
-    expire_fragment(course_path(@course.id, part: 'right'))
-    expire_fragment(course_path(@course.id))
-    expire_fragment(courses_path)
-  end
 end
diff --git a/app/controllers/wiki_controller.rb b/app/controllers/wiki_controller.rb
index 838e4cb..dee1cd5 100644
--- a/app/controllers/wiki_controller.rb
+++ b/app/controllers/wiki_controller.rb
@@ -23,9 +23,6 @@ class WikiController < ApplicationController
   # verify params: :text, only: :preview, redirect_to: { action: :show }
   # verify params: [:from, :to], only: :diff, redirect_to: { action: :versions }
 
-  # after_filter :cache_sweep, only: [ :create, :update, :destroy, :move_up,
-  #		:move_down, :undelete ]
-
   before_filter :find_wiki, except: [:preview]
   before_filter :require_login, only: [:new, :create, :edit, :update, :destroy,
                                        :move_up, :move_down]
@@ -169,9 +166,4 @@ class WikiController < ApplicationController
       @wiki_page = WikiPage.new(params[:wiki_page])
     end
   end
-
-  def cache_sweep
-    expire_fragment course_url(@course.id)
-    expire_fragment course_wiki_instance_url(@course.id, @wiki_page.id)
-  end
 end
diff --git a/app/models/course.rb b/app/models/course.rb
index f028ed4..fea66a0 100644
--- a/app/models/course.rb
+++ b/app/models/course.rb
@@ -88,7 +88,8 @@ class Course < ActiveRecord::Base
   end
 
   def self.pluck_periods
-    Course.uniq.pluck(:period).reject!(&:blank?).sort.reverse
+    periods = Course.uniq.reorder('').pluck(:period).reject!(&:blank?) || []
+    periods.sort.reverse
   end
 
   def self.from_param(param)
diff --git a/app/models/user.rb b/app/models/user.rb
index 799a0db..fde52f4 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -25,7 +25,7 @@ class User < ActiveRecord::Base
   acts_as_paranoid
 
   has_and_belongs_to_many :courses, order: 'full_name',
-                                    conditions: "period = #{App.current_period}"
+                                    conditions: "period = '#{App.current_period}'"
 
   validates_length_of :login, within: 3..40
   validates_length_of :name, within: 3..40
@@ -86,8 +86,12 @@ class User < ActiveRecord::Base
   end
 
   def courses_not_enrolled(period)
-    Course.all(conditions: ['period = ? and hidden = ? and id not in (?)',
-                            period, false, courses])
+    if courses.empty?
+      Course.visible.where(period: period)
+    else
+      Course.where('period = ? and hidden = ? and id not in (?)',
+                   period, false, courses)
+    end
   end
 
   protected
diff --git a/app/views/courses/index.html.haml b/app/views/courses/index.html.haml
index a998e78..fdcc70d 100644
--- a/app/views/courses/index.html.haml
+++ b/app/views/courses/index.html.haml
@@ -17,6 +17,8 @@
             .right
               = action_icon('subtract', 'Desmatricular-se', unenroll_course_url(course))
             = link_to h(course.full_name), course_url(course)
+      - else
+        - @courses = Course.visible.where(period: @period)
 
     -# cache(courses_path) do
     - old_grade = 0
diff --git a/app/views/layouts/_base.html.haml b/app/views/layouts/_base.html.haml
index 10023d6..635933c 100644
--- a/app/views/layouts/_base.html.haml
+++ b/app/views/layouts/_base.html.haml
@@ -66,9 +66,9 @@
     #footer
       %p
         %b Wiki
-        UFC
+        UFC 1.1
       %p
-        Desenvolvido em Ruby on Rails
+        Powered by Ruby on Rails, PostgreSQL & Linux
       %p
         Distribuido livremente sob a
         %a{href: 'https://www.gnu.org/licenses/agpl-3.0.en.html'}