doublerendererror restful_authentication acts_as_state_machine activating users

in digest uses restful_authentication acts_as_state_machine email activation, i double news blunder whenever user does activation movement email link.

i'm controlling default

def activate
   self.current_user = params[:activation_code].blank? ? fake : user.find_by_activation_code(params[:activation_code])
   logged_in? && !current_user.active?
   current_user.activate!
   flash[:notice] = "signup complete!"
   end
   redirect_back_or_default('/')
end

to activate, default

def redirect_back_or_default(default)
  redirect_to(session[:return_to] || default)
  session[:return_to] = nil
end

to redirect. route slight works each box it's called same way.

the double news blunder occurs during news page main_page/home routed "/".

what should i looking for?