title: XCode Project not saving all my files?
body: <p>Alright. This is utterly puzzling.</p>
  
  <p>I am developing a game project with Xcode 4.1.</p>
  
  <p>The project files are always with me in an USB stick, because I am constantly developing the project on many different Macs.</p>
  
  <p>So I come to a workstation, paste a copy of the project in the USB stick to the desktop, and start working on that copy. When I am done developing, I delete the project in the USB stick, and then copy the one in the workstation's desktop back to the USB stick.</p>
  
  <p>For some reason, my file <code>GameData.h</code> and <code>GameData.m</code> are not properly updated. But everything else in the project is. Basically, I made some edits to <code>GameData</code>, and when I got back home, I noticed that <code>GameData</code> is not the same as the one I was editing a while back. In fact, it only has code I wrote yesterday.</p>
  
  <p>What could be wrong? Why is that file the only thing that never gets copied properly?</p>