title: Strange Error with Push Segue
body: <p>I just created a calculator app with storyboards using two views. I started my simulator, and everything worked fine at first. On the first screen, I was able to use the "Calculator" button to switch to the second screen, and on the second screen I had a button to go back to the main menu. But when I switched from the main menu back to the calculator a second time, the app crashed, and the following error occurred:</p>
  
  <blockquote>
    <p>2013-02-21 20:55:36.556 CTS Calculator[22637:c07] <strong>* Terminating app
    due to uncaught exception 'NSGenericException', reason: 'Could not
    find a navigation controller for segue 'To Calculator'. Push segues
    can only be used when the source controller is managed by an instance
    of UINavigationController.'
    *</strong> First throw call stack: (0x15a9012 0x12b6e7e 0x650f31 0x642b99 0x642c14 0x12ca705 0x1fe2c0 0x1fe258 0x2bf021 0x2bf57f 0x2be6e8
    0x22dcef 0x22df02 0x20bd4a 0x1fd698 0x260bdf9 0x260bad0 0x151ebf5
    0x151e962 0x154fbb6 0x154ef44 0x154ee1b 0x260a7e3 0x260a668 0x1faffc
    0x1ecd 0x1df5) libc++abi.dylib: terminate called throwing an exception
    (lldb)</p>
  </blockquote>
  
  <p>I am not sure why this did not happen the first time I pushed the calculator button. I have a custom segue transition going back to the menu, but not from the menu to the calculator. My navigation controller is set up fine, I believe. Any ideas what the problem might be?</p>