iPad/iPhone touch event to trigger/fix hover on iOS5.1

Question

If anyone can help I'm having a problem with my hover but only on ipad running iOS 5.1, the hover on iOS 7.1 shows normally.

This is an example of my menu

<div class="wrapper clearfix">
  <nav class="clearfix">
    <ul class="menu clearfix">
      <li><a href="#sobre-a-501st">SOBRE A 501ST</a>
         <ul>
           <li><a href="link">News 501st Legion</a></li>
           <li><a href="link">mission</a></li>
           <li><a href="link">Origin</a></li>
           <li><a href="link">fax</a></li>
           <li><a href="link">Protocols</a></li>
           <li><a href="link">Testemonies</a></li>
          </ul>
      </li>
</div>

plus other menus in between the div

and here my CSS

nav li:hover, nav li:active{
    background-color: rgb( 179, 44, 12 );
    border-radius: 2px 2px;
    display: inline-block;
    opacity: 1;
    visibility: visible;
    margin-left: 0;
}

nav li:hover ul, nav li:active ul{
    display: block;
}