Wrong calendar owner - how to change?

[Jay2k1]

I have two or three co-workers that share the same problem:

They use thunderbird w/ ligntning. Whenever they create an appointment and invite others, my email address is displayed as sender, not theirs. This means I get lots of "Yeah I'll be there" and "Sorry, no time" mails for appointments that I haven't created - and the people making these appointments wonder why they don't get any response.

First I thought it would be a local problem, somehow related to thunderbird, because when creating an appointment from the web interface and inviting others, it works as expected.

But I couldn't find any setting in TB where you could put a different sender address for the calendar. I tried deleting and recreating the calendar in Lightning, at this point I noticed that we're using CalDAV when opening calendars in Lightning. I remembered that the whole DAV thing is based on port 80, so I tried opening the calendar URL in a webbrowser, and now things get interesting. The user name of an affected co-worker is petersen, so I went to http://zimbraserver.ourdomain.de/dav/petersen/Calendar. My username is klostermann, that's an admin account btw.

This is what I got in the browser:

Request

	Authenticated user:	petersen@ourdomain.de
	Current date:		Mon Jan 25 13:46:50 CET 2010

Resource

	Name:			Calendar
	Path:			/Calendar
	Date:			Mon Jun 08 11:26:16 CEST 2009
	Owner account Id:	31dd8efd-824f-4dd9-b1e1-4af3161633c1
	Owner account name:	klostermann@ourdomain.de

Properties
...

This leads to two questions:
1. What the hell? (as in: how can this happen?)
2. Where and how can I change this "ownership" back to the account the calendar belongs to and is stored in?

[Jay2k1]

Hello,

can anybody tell me how exactly the CalDAV thing works? Is there a folder somewhere on the server where automatically generated XML files for CalDAV reside? Or does anyone have any other ideas what to test or where to look?
Apparently the webserver providing the DAV interface is jetty, but I couldn't find out more about where CalDAV information is stored or provided or how it is parsed.


EDIT: I just created a new account in zimbra (called tester) and went to http://zimbraserver/dav/tester/Calendar in Firefox. When asked for credentials, I logged in with 'tester' and the corresponding password. And again, owner of that calendar is the klostermann account. So everytime I create a new user, CalDAV reports the wrong owner for the 'Calendar' folder. Interestingly, when I go to http://zimbraserver/dav/tester/ (without Calendar), the owner is the user tester.