ActionWebService dispatch problem

Rails
1

Hello,

I am having a problem with an extremely simple web service using
ActionWebService. This is basically ‘Hello World’ type of web service:

data_loader_api.rb:

class DataLoaderApi < ActionWebService::API::Base
  api_method :version,  :returns => [:string]
end

data_loader_controller.rb:

class DataLoaderController < ApplicationController
  web_service_dispatching_mode :direct
  wsdl_service_name 'data_loader'
  web_service_scaffold :invoke
  web_service_api DataLoaderApi

  def version
    return "1.0"
  end
end

Regardless how I tweak the definition of the method I always get the
following error:

ActionWebService::Dispatcher::DispatcherError in
DataLoaderController#invoke_submit

no such method ‘Version’ on API DataLoaderApi (version)

Your help will be greatly appreciated. Thank you in advance.