title: Codeigniter is not showing 404 error page
body: <p>I'm developing a new website using codeigniter, this is my first codeigniter experience. I suspect that there is something not working with the 404 error, when I try to load a controller that does not exist, or a wrong function of an existing controller, I get back the standard webserver 404 error, and not the codeigniter one.</p>
  
  <p>I did not touch the "404_override" option in the route config file.
  Is it normal? I expect (but maybe I'm wrong) that in these cases the show_404() function is called.</p>