title: UIWebView background is set to Clear Color, but it is not transparent
body: <p>I'm developing an iOS 4 application using iOS SDK latest version and XCode 4.2.</p>
  
  <p>I have a XIB with a <code>UIWebView</code> with <strong>Alpha = 1.0</strong>, <strong>Background</strong> set to <strong>Clear Color</strong> and <strong>Opaque</strong> is not set. On this XIB I setup an image as background with this code:</p>
  
  <pre><code>- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
  {
      self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
      if (self) {
          UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"AboutBackground.png"]];
          self.view.backgroundColor = background;
          [background release];
      }
      return self;
  }
  </code></pre>
  
  <p>The <code>UIWebView</code> is showing an static html:</p>
  
  <pre><code>&lt;html&gt;&lt;head&gt;&lt;/head&gt;&lt;body style=\"margin:0 auto;text-align:center;background-color: transparent; color:white\"&gt;...&lt;/body&gt;&lt;/html&gt;
  </code></pre>
  
  <p>On iOS 5 simulator, its background is transparent, but on an iOS 4 device is grey.</p>
  
  <p>Any clue?</p>