If you get a warning in the new Xcode 5 on the lines of:
Apps that include an armv7s architecture are required to include an armv7 architecture
warning: iPhone apps should include an armv7 architecture (current ARCHS = "armv7s")
There's probably something messed in your
project.pbxproj file. What a news....
But don't panic the fix is easy, just go in the Build Settings of your designated target, find the Architectures option and select "Standard" from the dropdown menu.
Note: "Standard" may be selected already. If that's the case... just select another option, save, and select "Standard" again. Crazy isn't it?
That did the trick for me... Hope it helps.
Happy coding! :)