MacOS – Errors publishing from Calendar app to WebDAV Share on same machine

I am currently attempting to publish a calendar in OS X 10.8. The calendar is a local "On My Mac" calendar residing within iCal/Calendar on the Mac. The same Mac has Server app installed. I have configured the Server app with a single File Share (named "webcal"), which is provisioned to share over WebDAV only. I have also setup Open Directory and created a user account to access this WebDAV share.

As a test, I opened up Finder > Connect to Server. Using the credentials, I successfully was able to mount https://localhost/webcal and read/write to the share. However, when I attempt to publish into this share directly from iCal/Calendar, I receive the following error message:

The calendar “Untitled” couldn’t be published. http://kitchenipad@localhost/webcal/Untitled.ics is not a location that supports this request.

By checking in Console I was able to locate the following corresponding entry:

7/10/13 1:27:28.186 PM Calendar[6311]: Validation error: Error Domain=NSCocoaErrorDomain Code=1570 "publication is a required value." UserInfo={
    CalManagedObjectType = CalManagedPublicationError;
    NSLocalizedDescription = "publication is a required value.";
    NSValidationErrorKey = publication;
    NSValidationErrorObject = "<CalManagedPublicationError: 0x7fbcbd70cee0> (entity: PublicationError; id: 0x7fbcbd7dfab0 <x-coredata://60115C98-1B7D-4B6F-B812-690F22C8374C/PublicationError/p45> ; data: {\n    code = 405;\n    domain = CoreDAVHTTPStatusErrorDomain;\n    publication = nil;\n    userInfo = nil;\n})";
}

Due to the project I'm working on I will need to have WebDAV and iCal client working on the same physical system. I'd like to avoid having to virtualize the server as well. Does anyone have a clue as to why this might not be working?