ci sono un paio di errori nel codice ma non attribuirei a questi la causa.
hai risolto la questione?
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html>
<head>
    <title></title>
    <style type="text/css">
        .style1 {
            width: 540px;
            height: 960px;
        }
    </style>
</head>
<body>
      
       <a name="Recapiti">
       <map id="FPmap0" name="FPMap0">
        <area onclick="confirm('Be sure you have placed your order before pressing redeem');"  href="share.html" shape="rect" coords="409, 58, 524, 111" />
        </map>
        <img class="style1" src="Screenshot_2015-10-31-09-27-04.png" usemap="#FPMap0" />
        </a>

</body>
</html>