title: Image in jQuery Mobile back button doesn't appear
body: <p>I've set-up jQueryMobile plugin into my blog mobile version by the instruction of jQueryMobile documentation.</p>
  
  <pre><code>&lt;link rel="stylesheet" href="http://code.jquery.com/mobile/1.0a2/jquery.mobile-1.0a2.min.css" /&gt;
  &lt;script src="http://code.jquery.com/jquery-1.4.4.min.js"&gt;&lt;/script&gt;
  &lt;script src="http://code.jquery.com/mobile/1.0a2/jquery.mobile-1.0a2.min.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>and description page is as follow</p>
  
  <pre><code>&lt;!DOCTYPE html&gt; 
  &lt;html&gt; 
      &lt;head&gt;
      &lt;meta charset="utf-8" /&gt; 
      &lt;title&gt;Against All Odds&lt;/title&gt; 
      &lt;link rel="stylesheet" href="http://code.jquery.com/mobile/1.0a2/jquery.mobile-1.0a2.min.css" /&gt; 
      &lt;link rel="stylesheet" href="_assets/css/jqm-docs.css"/&gt;
      &lt;script src="http://code.jquery.com/jquery-1.4.4.min.js"&gt;&lt;/script&gt;
      &lt;script type="text/javascript" src="http://code.jquery.com/mobile/1.0a2/jquery.mobile-1.0a2.min.js"&gt;&lt;/script&gt;
  &lt;/head&gt; 
  
  &lt;body&gt; 
  
  &lt;div data-role="page"&gt;
      &lt;div data-role="header"&gt;
          &lt;h1&gt;my title&lt;/h1&gt;
      &lt;/div&gt;&lt;!-- /header --&gt;
      &lt;div data-role="content"&gt;
              my description
      &lt;/div&gt;&lt;!-- /content --&gt;
  &lt;/div&gt;&lt;!-- /page --&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Unfortunately, the image in back button doesn't appear in my page. And I've also put jQuerymobile images folder into my project page. Is there any configuration did I forget to setup?</p>
  
  <p><img src="https://i.stack.imgur.com/Plrws.png" alt="alt text"></p>