From: Felipe Jaekel <fkjaekel_at_gmail.com>
Date: Fri, 4 Apr 2008 09:29:32 -0300

I have a drop down with a processValueChange handler. When the form is
submitted for the first time, even if I don't change the selection the event
is fired. Debugging the ValueChangeEvent instance, the oldValue property is
null. Shouldn't the oldValue property contain the value of the selected item
when the page was first rendered?