webcalendar module with public (anonymous) access: "Not Found The requested URL /drupal/user was not..."

I wish for users who are not logged in to be able to view the public calendar through drupal's webcalendar integration module. However, when I am not logged in and click on the "calendar" link I get: "Not Found The requested URL /drupal/user was not found on this server."

The webcalendar integration module appears to work fine for authenticated users.

I have played with the settings for access in Drupal to no avail.

Thanks,

-John