title: Setting a text = a string crashes my program
body: <p>I am new at this so be gentle.
  I have this function:</p>
  
  <pre><code>- (void) Morepoint {
      gscore ++;
      scoreString = [NSString stringWithFormat:@"%i", gscore];
      lblscore.text = scoreString;
  }
  </code></pre>
  
  <p>Where <code>gscore</code> is a global. <code>scoreString</code> is a NSString and <code>lblscore</code> is a label.
  Every time I insert the function in my gameloop, the program stops to run.
  Can anyone figure that out?
  If I call the function from outside my gameloop, everything works fine, why?</p>