title: CCLabelAtlas setString doesn't update label
body: <p>I have a CCLabelAtlas that I have on a layer to display the current score within my game...the problem that I am having with it is that it does not update when I use <code>[scoreLabel setString:]</code>.  Here's how I have it laid out:</p>
  
  <p>In the header:</p>
  
  <pre><code>@interface GameScene : CCLayer {
  ...
  
  CCLabelAtlas* scoreLabel;
  }
  </code></pre>
  
  <p>And in the init:</p>
  
  <pre><code>scoreLabel = [[CCLabelAtlas alloc] initWithString:@"0" charMapFile:@"scoreCharMap.png" itemWidth:6 itemHeight:8 startCharMap:'.'];
  [scoreLabel setPosition:ccp(105, 414)];
  [self addChild:scoreLabel z: 6];
  </code></pre>
  
  <p>scoreCharMap.png is a custom map that includes <code>./0123456789</code> of my desired font.  When the score is changed, I attempt to do this to get the label to update with the current score:</p>
  
  <pre><code>NSString* str = [[NSString alloc] initWithFormat:@"%d", [[GameRunner sharedInstance] currentScore]];
  [scoreLabel setString: str];
  [str release];
  [scoreLabel draw];
  </code></pre>
  
  <p>Problem is that it doesn't ever update - it just sits there and displays 0.  I know for a fact due to breakpoints and debugging that setString is being called, and that the string that it should be displaying is correct - but it just doesn't update.  Hard-coding the value and saying <code>[scoreLabel setString:@"1234"]</code> does nothing, either.  What am I doing wrong here?  I am using Cocos2d 0.99 - thanks in advance!</p>