Year-only custom data date field doesn't work on public profiles

http://www.capitolpagealumni.org/?page=CiviCRM&q=civicrm/contribute/transact&reset=1&id=1

See the "year" field down at the bottom of this contribution page profile. This is a custom data "date" field configured for year only. It works on the 'back office' side, but not in this public contribution page profile.

The date picker doesn't work.

If you type in a year (try it) and click the submit button the date is erased.