All generators working with Rails 2 and 3. Tested in app for Rails 2 and 3.

lib/generators/paperclip/paperclip_generator.rb

-class PaperclipGenerator < Rails::Generators::Base
-  include Rails::Generators::Migration
+require 'rails/generators/active_record'
 
+class PaperclipGenerator < ActiveRecord::Generators::Base
   desc "Create a migration to add paperclip-specific fields to your model."
 
-  argument :attachment_class, :required => true, :type => :string, :desc => "The class to migrate.",
-           :banner => "ClassName"
   argument :attachment_names, :required => true, :type => :array, :desc => "The names of the attachment(s) to add.",
            :banner => "attachment_one attachment_two attachment_three ..."
 
@@ -19,7 +17,7 @@ class PaperclipGenerator < Rails::Generators::Base
   protected
 
   def migration_name
-    "add_attachment_#{attachment_names.join("_")}_to_#{attachment_class.underscore}"
+    "add_attachment_#{attachment_names.join("_")}_to_#{name.underscore}"
   end
 
   def migration_file_name
@@ -30,8 +28,4 @@ class PaperclipGenerator < Rails::Generators::Base
     migration_name.camelize
   end
 
-  def self.next_migration_number(dirname) #:nodoc:
-    Time.now.strftime("%Y%m%d%H%M%S")
-  end
-
 end

lib/generators/paperclip/templates/paperclip_migration.rb.erb

 class <%= migration_class_name %> < ActiveRecord::Migration
   def self.up
 <% attachment_names.each do |attachment| -%>
-    add_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_file_name, :string
-    add_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_content_type, :string
-    add_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_file_size, :integer
-    add_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_updated_at, :datetime
+    add_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_file_name, :string
+    add_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_content_type, :string
+    add_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_file_size, :integer
+    add_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_updated_at, :datetime
 <% end -%>
   end
 
   def self.down
 <% attachment_names.each do |attachment| -%>
-    remove_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_file_name
-    remove_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_content_type
-    remove_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_file_size
-    remove_column :<%= attachment_class.underscore.camelize.tableize %>, :<%= attachment %>_updated_at
+    remove_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_file_name
+    remove_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_content_type
+    remove_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_file_size
+    remove_column :<%= name.underscore.camelize.tableize %>, :<%= attachment %>_updated_at
 <% end -%>
   end
 end

lib/paperclip.rb

@@ -337,7 +337,7 @@ module Paperclip
       @_paperclip_attachments ||= {}
       @_paperclip_attachments[name] ||= Attachment.new(name, self, self.class.attachment_definitions[name])
     end
-    
+
     def each_attachment
       self.class.attachment_definitions.each do |name, definition|
         yield(name, attachment_for(name))

lib/paperclip/railtie.rb

@@ -4,7 +4,7 @@ module Paperclip
   if defined? Rails::Railtie
     require 'rails'
     class Railtie < Rails::Railtie
-      config.after_initialize do
+      initializer "paperclip.insert_into_active_record" do
         Paperclip::Railtie.insert
       end
       rake_tasks do

rails/init.rb

+puts "THIS IS THE RAILS/INIT.RB FILE"
 require 'paperclip/railtie'
 Paperclip::Railtie.insert