Change event does not fire in IE - jquery 1.4.2

Change event does not fire in IE - jquery 1.4.2

If you have a text input with a change event bound to it, the event wont fire initially if that input is given focus by a .focus() call.

works in browsers other than IE

code to test: 

<!DOCTYPE html>
<html>
<head>
    <script type='text/javascript' src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
    <script type='text/javascript'>
        $(function() {
            $('#btn').click(function() { $("#tb1").focus();  });
            $("#tb1").change(function() { alert($(this).val()); });
        });
    </script>
</head>
<body>
    <input type='text' id='tb1' />  <input type='button' id='btn' value='Button' />
</body>
</html>