[Evolution] publish free/busy data to a .mac account

[Mike Linksvayer <ml gondwanaland com>]

Hi.  I'm using Evolution 2.4.1, specifically 2.4.1-0ubuntu7

I'd like to publish free/busy data to a .mac account, but I can't seem to figure
out the proper "publishing location" to give to Evolution (calendar) via
Edit|Preferences|Free/Busy.

When viewing others calendars I use
http://ical.mac.com/dot_mac_account_name/calendar_name or
webcal://ical.mac.com/dot_mac_account_name/calendar_name.ics

(with dot_mac_account_name and calendar_name replaced with real values)

I've tried giving Evolution many variations on these, apparently to no avail,
and no feedback is given when publishing free/busy data, apart from --debug,
which says

(evolution:10174): calendar-gui-WARNING **: itip-utils.c:1399: Could not publish
Free/Busy: 400: Bad Request

Anyone have any leads regarding free/busy publishing URLs for .mac account
calendars?

Thanks!

Mike