Test Case Boilerplate
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HTML
<script src="http://code.jquery.com/ui/jquery-ui-git.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/jquery-ui-git.css">
<h3>Row With Hidden Items (IE8 mode)</h3>
<table border='1' cellpadding='2' cellspacing='0'>
<thead>
<tr id="hidden">
<th>one</th>
<th>two</th>
<th style="display:none">three</th>
<th style="display:none">four</th>
<th>five</th>
<th>six</th>
<th>seven</th>
<th>eight</th>
</tr>
</thead>
</table>
<div id="out"></div>
JavaScript
$(function() {
$("#hidden").sortable({
"axis": "x",
"placeholder": 'ui-state-highlight',
"forcePlaceholderSize":true});
$("#out").append("<p>nvis="+$("thead tr th:not(:hidden)").length+"</p>");
});