jQuery Datepicker keeps showing when closed in IE7

Question

I have an issue with datepicker continually reappearing when the Done button is clicked. But only in IE7, not Firefox - it stays hidden. I suspect the problem is datepicker is shown on focus and the host input is being refocused in IE when datepicker is closed, triggering it to come up again.

JQ 1.3.2 (also tried 1.4.2) JQUI 1.7.2.

$(".period").datepicker({
    clickInput: true,
    dateFormat: 'MM yy',
    changeMonth: true,
    changeYear: true,
    showButtonPanel: true,
    onClose: function(dateText, inst) {
        ...
        $(this).datepicker('setDate', new Date(year, month, 1));
    }
});