title: Xcode 4 is not indexing my project
body: <p>I have a project where Xcode 4 stopped indexing. As a consequence neither the complete class browser (symbol navigator) nor code sense work. 0 Classes and Protocols etc. are shown.
  I restarted indexing process by removal of some temporary files in the derived data and the xcodeproj area. But this does not help.
  Does anyone know what can Xcode prevent from indexing?</p>
  
  <p>I rebuilt the whole project and hopefully found the reason: In <em>my-Prefix.pch</em> file I included <strong>#import &lt;myheader.h></strong>, where <em>myheader.h</em> was resolved via Header Search Path. When I changed this line to <strong>#import "myheader.h"</strong>, code sense and class browser worked again.</p>