title: UILabel custom fonts works only on iOS7
body: <p>i am subclassing a <code>UILabel</code> to set a custom font so i can use it across header bars in my app. so i have created a <code>HeaderLabel</code> class that inherit from <code>UILabel</code> and i have added this code to set the font :</p>
  
  <pre><code>- (id)initWithCoder:(NSCoder *)coder {
      self = [super initWithCoder:coder];
         if (self) {
  
         self.font = [UIFont fontWithName:@"fbTypoPas-Black" size:34];
         self.textColor = [UIColor whiteColor];
      }
      return self;
  }
  </code></pre>
  
  <p>i am not holding any reference to the<code>HeaderLabel</code>  from <code>IB</code> just setting the text i want.
  it works well on <code>IOS</code> 7, <code>IOS</code> 6 and 5 not seem to be working</p>
  
  <p><img src="https://i.stack.imgur.com/fIxTO.png" alt="enter image description here"></p>