title: Size of label changes after being set, depending on string
body: <p>I am facing an issue in getting the correct frame for two different strings. I am running two strings through the below code:</p>
  
  <pre><code>UILabel *myLabel = [[[UILabel alloc] initWithFrame:CGRectZero] autorelease];
  myLabel.lineBreakMode = UILineBreakModeWordWrap;
  myLabel.numberOfLines = 2;
  myLabel.textAlignment = UITextAlignmentCenter;
  myLabel.font = [UIFont boldSystemFontOfSize:11];
  myLabel.text = @"About Stores"
  myLabel.text = @"About Rivers"
  
  CGSize myLabelSize = CGSizeMake(70,28);
  [myLabel sizeWithFont:myString.font     // &lt;-- One of two strings
      constrainedToSize:aLabelSize 
          lineBreakMode:UILineBreakModeWordWrap];
  </code></pre>
  
  <p>Result for <code>myString1</code> => Width: 70, Height: 28<br>
  Result for <code>myString2</code> => Width: 70, Height: 14</p>
  
  <p>Why there is a difference here?</p>