I could not reproduce this error.
I've tested the below in Windows Phone 8 using a Worklight project (with jQuery Mobile 1.4.3); everything is working...
Additionally, see @vishal_g's comment.
HTML
<!DOCTYPE HTML>
<html>
<head>
...
...
<link href="jqueryMobile/jquery.mobile-1.4.3.css" rel="stylesheet">
<link rel="stylesheet" href="css/main.css">
<script>window.$ = window.jQuery = WLJQ;</script>
<script src="jqueryMobile/jquery.mobile-1.4.3.js"></script>
</head>
<body style="display: none;">
<div data-role="page" id="page">
<div data-role="content" style="padding: 15px">
<ul data-role="listview" id="list" data-autodividers="true">
<li><a href="#">Adele</a></li>
<li><a href="#">Agnes</a></li>
<li><a href="#">Billy</a></li>
<li><a href="#">Calvin</a></li>
</ul>
</div>
<button onclick="emptyList()">empty list</button>
</div>
<script src="js/initOptions.js"></script>
<script src="js/main.js"></script>
<script src="js/messages.js"></script>
</body>
</html>
JavaScript
function wlCommonInit(){
}
function emptyList() {
$("#list").listview().empty();
}