imap ACL via Kontact

[Michael]

Hi List.

With kontact there is some "Access Control" tab in the "Folder Properties" dialog. I can see the permissions and change those via roundcube, but in kontact all buttons (add/edit/remove entry) are greyed out. 

I tried different kontact versions (4.10.5 in Ubuntu 13.04 and 4.11.3 in arch linux) and Kolab 3.0 Servers (deb (Debian) and rpm (CentOS) installations). Freshly installed, some test users created and test mails sent.

I even used openssl (s_client -connect [ip]:993) to login to the mailbox and did some getacl/setacl commands. It seems cyrus is working fine. 

Is KDE Kontact known buggy here? How to "ungray" those buttons?

Regards
Michael