has_many_polymorphs

Hello

Has anyone tried to use the has_many_polymorphs plugin? I have added
the following line into environment.rb just before
Rails::Initializer.run:

require 'has_many_polymorphs'

... created two models:

class CreateOwnerships < ActiveRecord::Migration
  def self.up
    create_table :ownerships do |t|
      t.references :owner, :polymorphic => true
      t.references :property, :polymorphic => true
      t.column :created_on, :timestamp
    end
  end

  def self.down
    drop_table :ownerships
  end
end

class CreateTasks < ActiveRecord::Migration
  def self.up
    create_table :tasks do |t|
      t.column :name, :string, :null => false
      t.column :description, :text
      t.column :complete, :boolean, :null => false
      t.column :weight, :float, :null => false
    end
  end

  def self.down
    drop_table :tasks
  end
end

and tried to run `rake db:migrate` and got the following message:

** has_many_polymorphs: rails environment detected
** has_many_polymorphs: preloading parent model Ownership
** has_many_polymorphs: Ownership could not be preloaded:
#<ActiveRecord::StatementInvalid: Mysql::Error: Table
'mydb.ownerships' doesn't exist: SHOW FIELDS FROM ownerships>
rake aborted!

what's wrong?

Thanks