title: NSRunLoop working OK on Simulator, Crashes iDevice
body: <p>I'm working on an iOS App (FW: 5.0+ &amp; ARC) which needs to update second by second.</p>
  <p>Currently, I have this within a method (which is called in a performSelector when -ViewDidLoad):</p>
  <pre><code>-(void)FireOnload {
  counter = [NSTimer timerWithTimeInterval:1.0 target:self selector:@selector(countDownTime) userInfo:nil repeats:YES];
  [counter fire];
  [[NSRunLoop mainRunLoop] addTimer:counter forMode: NSDefaultRunLoopMode]; // &lt;-- Causing Problem
  }
  
  -(void)countDownTime
  {
  double timeNow = [[NSDate date] timeIntervalSince1970];
  double timeLeft = timeEnding - timeNow;
  
  if(timeLeft &lt; 60) // Less then 60 seconds, do something.
  {
     //Do Stuff
  }
  
  }
  </code></pre>
  <p>the <code>counter</code> variable is called in the header as NSTimer.
  I explicitly call <code>[counter fire]</code> so it is called as soon as the view is loaded, not after 1 second.</p>
  <p><strong>This works fine</strong> in the iOS Simulator and will fire every second, but when it goes to the iDevice, it crashes.</p>
  <p>I've commented out the <code>NSRunLoop</code> line, and the iDevice does not crash. However, it no longer updates every second.</p>
  <p>What am I doing wrong here?</p>