[TYPO3-calendar] cal frontend editing list of calendars

[Christoph Hermann]

Hello,

i have successfully installed tt_address, cal and configured it for 
frontend editing.
So far i have succeeded in allowing a frontend user group to have access 
to the "create event" form.

My problem is that the form contains a field to select the calendar and 
this list is *empty*.

Even setting the calendar_id default to "1" and marking it as non-
required and public = 0 still makes the field appear (still empty).

Is there a way to specify which calendar should be used?

Thank you in advance!
Christoph