I know that there is a jQuery UI element to this issue but as the below code works with 1.4.2 a change in 1.4.3 is causing the issue. With the below code the dialog does not display unless the buttons line is removed.

<div id="testdiv">Test content<div>

<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/smoothness/jquery-ui.css" rel="stylesheet" type="text/css" />

<script type="text/javascript" src="http://code.jquery.com/jquery-1.4.3rc1.js"></script>

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/jquery-ui.min.js"></script>

<script type="text/javascript">

$(document).ready(function () {

$("#testdiv").dialog({

buttons: { "OK": function () { alert($(this).html()); }}

});

});

</script>