Lost access to shared imap contacts folder

[Johannes Graumann]

I backuped my 2.1 installation and dabbled around with 2.2-rc1.
I discarded the 2.2 idea, after realizing that the installation process had
not configured properly all components.
I deleted the /kolab directory and restored my original 2.1 install.
Now I don't have access anymore to  a shared contacts folder I set up
previously.
According to the web management interface It's supposed to be there,
it's owned by the right group, my user is in that group. cyradmin also shows
it to be there ...
kontact doesn't pull the contents any longer. 
Does anybody have any hints on what I might do about that?
Where to look?

Thanks, Joh