Datepicker in Gravity Forms not working in PopUp Pro

So when I put a gravity form into my PopUp, the datepicker will not work. However, I tested putting the same form on a regular page and it works beautifully. Can you help me figure out why the datepicker will not work in the pop up? You can recreate the issue by going to http://voltaoil.setteradvertising.com and clicking on the "Order Fuel" button in the top right corner. The pop up comes up, and if you scroll down the form, near the bottom is a datepicker field. If you go to the following: http://voltaoil.setteradvertising.com/test-form-datepicker/ you will see the form working as it should. Thanks for any help you can give me. I do have a support ticket into the Gravity forms people as well to see if they have any suggestions.