Position corrigée ne fonctionnant pas dans le navigateur mobile

Comment faire de la position de l'élément fixe dans navigateur Mobile (ios et android) ?
Élément défile toujours avec le code ci-dessous dans ios < 5 et android< 4

<html>
 <head>
<style>
     .fixed{
      position:fixed;
      top:0;
      left:0;
    }
</style>
</head>
<body>
     <div class="fixed">
     Hi I m Position Fixed 
     </div>
    <div>
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    </div>
</body>
</html>

source d'informationauteur Vicky Gonsalves