Well ... I've gotten it to work (sample code below, sorry for the muddled string I couldn't get it to display in the code blocks otherwise) ... but I'm wondering how YOU found this page?? This doesn't seem to be part of the latest jQuery Mobile release candidate ... so my guess is that it's not working for you because your JS and CSS references aren't pointing to the files that actually contain the corresponding code?
<!DOCTYPE html>
<html class="ui-mobile-rendering">
<head>
<meta charset="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>JQM popup test</title>
<link rel="stylesheet"
href="http://jquerymobile.com/branches/popup-widget/css/themes/default/jquery.mobile.css"/>
<script src="http://jquerymobile.com/branches/popup-widget/js/jquery.js"></script>
<script src="http://jquerymobile.com/branches/popup-widget/js/"></script>
</head>
<body>
<a href="#popupBasic" data-rel="popup">Tooltip</a>
<div data-role="popup" id="popupBasic">This is a completely basic popup, no options set.</div>
<div>Other</div>
<div>Random</div>
<div>Text</div>
</body>
</html>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…