jQM 1.4.4 icons not showing

jQM 1.4.4 icons not showing

I have just started using jQuery Mobile for an ASP.NET site which will have certain pages designed expressly for touch/tablet access. JQM certainly seems the way to go, but for some reason I am unable to get icons to show, even when I keep it very simple and only use CDN hosted JS and CSS, as follows:
  1. <!DOCTYPE html>
    <html>
    <head>
    <title>JQM icon test</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="http://code.jquery.com/mobile/1.4.4/jquery.mobile-1.4.4.min.css">
    <script src="http://code.jquery.com/jquery-1.11.1.min.js"></script>
    <script src="http://code.jquery.com/mobile/1.4.4/jquery.mobile-1.4.4.min.js"></script>
    </head>
    <body>
    <div data-role="page" id="pageone">
    <div data-role="header">
    <h1>Buttons With Icons</h1>
    </div>
    <div data-role="main" class="ui-content">
    <a href="#home" class="ui-btn ui-btn-inline ui-shadow ui-corner-all ui-icon-home ui-btn-icon-left" data-rel="dialog">Home</a>
    <a href="#options" class="ui-btn ui-btn-inline ui-shadow ui-corner-all ui-icon-grid ui-btn-icon-left" data-rel="dialog">Options</a>
    <a href="#search" class="ui-btn ui-btn-inline ui-shadow ui-corner-all ui-icon-search ui-btn-icon-left" data-rel="dialog">Search</a>
    <a href="#pagetwo" class="ui-btn ui-shadow ui-corner-all ui-icon-arrow-r ui-btn-icon-right">Next Page</a>
    <a href="#info" class="ui-btn ui-shadow ui-corner-all ui-icon-info ui-btn-icon-left" data-rel="dialog">Information</a>
    </div>
    <div data-role="footer" data-position="fixed">
    <h1>&copy; copyright statement</h1>
    </div>
    </div>
    </body>
    </html>

I can retrieve this page from my web server (IIS6) onto my desktop (Windows7, IE10) and all is fine. I can open the same page as a file on my tablet (MS Surface 2, Windows 8.1, IE11) and again it is fine. But if I retrieve the page from my web server onto the tablet, the layout is broken (no header shading, footer not at bottom of screen, button text not centred, button corners not rounded) and the icons are missing. I have tried clearing browser history on the tablet and recycling the application pool in IIS with no success. I am completely out of ideas as to what could be different. Any suggestions gratefully received.