CiviContribute Custom Page default checkbox doesn't work

Hi,
I have successfully set up a contribution page and added a CiviCRM Profile with a custom Alphanumeric Checkbox that has the 'Defaults' checked for 2 out of three checkboxes. When I then add the CiviCRM Profile to the contribution page via "Custom Page Elements" and view the contribution page the default checks are not on the form.

Essentially I'd like to provide a few checkbox options for things like newsletter, email updates, and volunteering, with the checkbox set to default for the first 2 and not checked for that last one. It work in the CiviCRM Profile, but not when it is on the Contribution page.

I also tried to duplicate what I want on the demo. The problem is on the demo as well.

Here is the preview of the CiviCRM Profile I put on the demo. You can see that the default checkboxes work here:
http://demo.civicrm.org/drupal/civicrm/admin/uf/group?action=preview&id=3&field=0

Here is the preview of the Contribution page I put on the demo. You can see the the checkbox defaults do not carry over to the contribution page:
https://demo.civicrm.org/drupal/civicrm/contribute/transact?reset=1&id=2

Thanks for such a great tool,
Scott