title: Can't archive anymore, yet "build for archive" still works (Xcode 4)
body: <p>Xcode is behaving rather strange right now:</p>
  
  <p>If I try to "Build for Archive" my app, the build process finishes without any errors or warnings. If I attempt to "Archive" though, it will throw a huge load of build errors at me. The errors (and the number of errors) are different every time I try.</p>
  
  <p>The app still runs fine on the simulator and on the device. I have successfully archived the same app before, although the last successful archive was created using Xcode 4.0.1 (now 4.0.2).</p>
  
  <p><strong>Live update:</strong></p>
  
  <p>Amongst the mass of errors there is one recurring issue: It seems like the app's pch file (precompiled header file) can't be found. I suppose this is the root error for all of the other issues. The question remains why it can't be found while archiving, despite being perfectly available to all other build types (and even "build for archive")?</p>
  
  <p>How can I overcome this error? If this is a bug in Xcode 4.0.2: Is there a way to archive a build without using the "Archive" option?</p>
  
  <p><strong>Edit:</strong>
  This may be another hint: Right after complaining that the pch couldn't be found, another error says "one or more PCH files were found, but they were invalid" - hokay...</p>