Can't get webrat to work with a Rails 2.0.2 app

Question

I have a simple test just to see if I can get webrat working that is failing.

class AuthenticationTest < ActionController::IntegrationTest
  def test_logging_in_with_valid_username_and_password
   get login_url
  end
end

With the above all I get in the error message is:

1) Error: test_logging_in_with_valid_username_and_password(AuthenticationTest): Webrat::PageLoadError: Page load was not successful (Code: 0): /Library/Ruby/Gems/1.8/gems/webrat-0.4.4/lib/webrat/core/session.rb:110:in request_page' /Library/Ruby/Gems/1.8/gems/webrat-0.4.4/lib/webrat/core/session.rb:205:in visit' (eval):2:in visit' ./test/integration/authentication_test.rb:6:in test_logging_in_with_valid_username_and_password'

Does anyone have a clue to what is wrong?

Thanks for the help.