diff --git a/app/models/group.rb b/app/models/group.rb
index 36953268..468c06d5 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -6,6 +6,7 @@ class Group < ActiveRecord::Base
   
   validates_length_of :name, :in => 1..25
   validates_uniqueness_of :name
+  validate :last_admin_on_earth, :on => :update
   
   # Returns true if the given user if is an member of this group.
   def member?(user)
@@ -32,8 +33,8 @@ class Group < ActiveRecord::Base
   end
 
   # add validation check on update
-  def validate_on_update
-    # error if this is the last group with admin role and role_admin should set to false
+  # Return an error if this is the last group with admin role and role_admin should set to false
+  def last_admin_on_earth
     if self.role_admin == false && Group.find_all_by_role_admin(true).size == 1 && self == Group.find(:first, :conditions => "role_admin = 1")
       errors.add(:role_admin, "Der letzten Gruppe mit Admin-Rechten darf die Admin-Rolle nicht entzogen werden")
     end
diff --git a/app/models/invite.rb b/app/models/invite.rb
index 88d802ae..b9c921eb 100644
--- a/app/models/invite.rb
+++ b/app/models/invite.rb
@@ -10,6 +10,8 @@ class Invite < ActiveRecord::Base
   validates_presence_of :group
   validates_presence_of :token
   validates_presence_of :expires_at
+  validate :email_not_already_registered, :on => :create
+
       
  protected
   
@@ -27,7 +29,7 @@ class Invite < ActiveRecord::Base
  private
 
   # Custom validation: check that email does not already belong to a registered user.
-  def validate_on_create
+  def email_not_already_registered
     unless User.find_by_email(self.email).nil?
       errors.add(:email, 'ist bereits in Verwendung. Person ist schon Mitglied der Foodcoop.')
     end
diff --git a/app/models/message.rb b/app/models/message.rb
index 9604d261..ccfd9768 100644
--- a/app/models/message.rb
+++ b/app/models/message.rb
@@ -19,9 +19,9 @@ class Message < ActiveRecord::Base
   validates_length_of :subject, :in => 1..255
   validates_inclusion_of :email_state, :in => EMAIL_STATE.values
 
+  before_validation :clean_up_recipient_ids, :on => :create
 
-  # clean up the recipients_ids
-  def before_validation_on_create
+  def clean_up_recipient_ids
     self.recipients_ids = recipients_ids.uniq.reject { |id| id.blank? } unless recipients_ids.nil?
     self.recipients_ids = User.all.collect(&:id) if sent_to_all == "1"
   end
diff --git a/app/models/page.rb b/app/models/page.rb
index 65b55e28..3ab33612 100644
--- a/app/models/page.rb
+++ b/app/models/page.rb
@@ -11,8 +11,8 @@ class Page < ActiveRecord::Base
   validates_presence_of :title, :body
   validates_uniqueness_of :permalink, :title
 
-  before_validation_on_create :set_permalink
-  before_validation_on_update :update_permalink
+  before_validation :set_permalink, :on => :create
+  before_validation :update_permalink, :on => :update
   after_update :create_redirect
 
   named_scope :non_redirected, :conditions => {:redirect => nil}