title: Custom images with UISlider doesn't show on the device
body: <p>Everything works on the simulator without a problem. However when I put it on my device it only show the <code>ThumbImage</code>. It is just really strange. I'm thinking this could be a iOS version issue or memory issue. My device is iPhone 3GS iOS 4.1. Xcode Version 3.2.5.</p>
  
  <pre><code>@interface BlueChalkSlider : UISlider {}
  @end
  
  @implementation BlueChalkSlider
  - (id)initWithCoder:(NSCoder *)decoder {
      if ((self = [super initWithCoder: decoder])) {      
          self.backgroundColor = [UIColor clearColor];
          [self setThumbImage:[UIImage imageNamed:@"Chalk.png"] forState:UIControlStateNormal];
          [self setMinimumTrackImage:[UIImage imageNamed:@"ChalklineBlue.png"] forState:UIControlStateNormal];
          [self setMaximumTrackImage:[UIImage imageNamed:@"ChalklineWhite.png"] forState:UIControlStateNormal];
      }
      return self;
  }
  @end
  </code></pre>