[Dovecot] shared mailbox - namespace

[c-schettner]

Hi all,
this is my last try to get help before giving up. I red the dovecot-wiki 
several times, but it doesn´t work.
I don´t know what´s wrong. If I open thunderbird I see the folder 
"public" but I cannot subscribe it.
I have dovecot 1.0.10. Yes it´s a little bit old but it is the latest 
version under debian packages.
Please see my configuration below.


here the content of: /etc/dovecot-acl/public

user=user1 at domain1.de rwl


here my /home/vmail
------------------------------------------------------------------
mail:/home/vmail# ls -l
insgesamt 32
drwx------ 6 vmail vmail 4096 2008-02-22 09:43 domain1.de
drwx------ 4 vmail vmail 4096 2008-02-15 16:56 domain2.de
-rw------- 1 vmail vmail 7762 2008-02-22 13:37 dovecot-deliver.log
-rw-r--r-- 1 root root 160 2008-02-22 09:40 globalsieverc
-rw------- 1 vmail vmail 204 2008-02-22 09:40 globalsievercc
drwx------ 5 vmail vmail 4096 2008-02-22 13:16 public
drwx------ 3 vmail vmail 4096 2008-02-18 09:08 web.de
-------------------------------------------------------------------


here a part of my dovecot.conf:

---------------------------------------------
mail_location = maildir:/home/vmail/%d/%n

namespace public {
separator = /
prefix = public/
location = maildir:/home/vmail/public
hidden = no
}

namespace private {
separator = /
prefix =
inbox = yes
}

mail_extra_groups = mail
#umask = 0077

protocol imap {

mail_plugins = acl
}

plugin {
#quota = maildir
acl = vfile:/etc/dovecot-acls
#trash = /etc/dovecot-trash.conf
}
------------------------------------------------

here the shared folder:

------------------------------------------------------------
mail:/home/vmail/public# ls -l
insgesamt 12
drwx------ 2 vmail vmail 4096 2008-02-22 12:14 cur
-rw-r--r-- 1 vmail vmail 0 2008-02-22 13:16 dovecot-shared
drwx------ 2 vmail vmail 4096 2008-02-22 12:14 new
drwx------ 2 vmail vmail 4096 2008-02-22 12:14 tmp
mail:/home/vmail/public#
-------------------------------------------------------------


Thanks,
Christian.