civipledge: not able to edit payment start date after pledge created

at this page
http://drupal.demo.civicrm.org/civicrm/contact/view?reset=1&cid=5

then press the pledge tab

-pledge made reads nov 17 2008

• under next payment date it reads dec 25 2008,

now look all the way to the right and click the VIEW link
-pledge made says dec 25 2oo8
-payment start says nov 17 2008

should next payment date and payment start have the same date ? if not please explain