Datepicker issue with Gravity Forms

Hi,

I'm setting up a site with the latest Wordpress 3.5.2. I am seeing a Javascript error in Firebug Console when clicking inside my Datepicker text box. The result is that the Datepicker popup doesn't appear.

TypeError: $.effects.effect is undefined

Check out this sample page that exemplifies the problem.

http://kenchapple.com/?page_id=4

Any ideas on how to fix this issue?

Please let me know if you need more information.

Thanks!
Ken