title: Target confusion at compile time
body: <p>I am working on a project, in xCode 4.5.2 with 2 targets T1 and T2.</p>
  
  <p>When I want to build T1, I get error messages about one file only belonging to T2.</p>
  
  <p>Obviously, even though I think the file belongs to T2, the compiler thinks differently.
  Where do I need to check? As far as I can see, I have done the necessary for the file to be inside T2 and not inside T1.
  But I must be forgetting something. Any idea?</p>
  
  <p>Thanks for any useful tip.</p>