change event for form elements not firing inside dialog when closed by "X"

A form element (textbox, textarea) usually triggers onchange

event when the element leaves focus (onblur) and the contents

of the element is changed. In Firefox (tested 6.0.2) the onchange

event is NOT firing when dialog is closed by clicking "X".

More precisely:

• open dialog with a textbox or textarea
• type something
• click "X" to close

I'm pretty sure it worked in earlier versions of FF (3.0 or older).

IE9 and Safari seem to work ok.

Testcase: http://www.colcode.com/bug/jquery-dialog-onchange-not-firing.html