[Dovecot] Error when trying to delete folders

[Bar Ziony]

Hi,

I'm using Dovecot 2.0.12 as an IMAP server. I'm using the lazy expunge 
plugin (2 namespaces - default and .EXPUNGED).

When trying to delete a folder, I get this error:
"Server Error: DELETE: Can't rename mailboxes across specified storages"

Is that related to the lazy expunge plugin? What does this error means 
exactly and how can I fix it?

`dovecot -n` output:
# 2.0.12: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-5-amd64 x86_64 Debian 6.0.2
auth_master_user_separator = *
lda_mailbox_autocreate = yes
listen = *
log_path = /var/log/dovecot/dovecot.log
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_gid = 1001
mail_location = maildir:~/Maildir:INDEX=/var/indexes/%n
mail_plugins = quota
mail_privileged_group = vmail
mail_uid = 1001
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character vacation subaddress comparator-i;ascii-numeric 
relational regex imap4flags copy include variables body enotify 
environment mailbox date
namespace {
   inbox = yes
   location =
   prefix =
   separator = /
   type = private
}
namespace {
   hidden = no
   list = yes
   location = maildir:~/Maildir/expunged
   prefix = EXPUNGED/
   separator = /
   type = private
}
passdb {
   args = scheme=md5-crypt username_format=%n /etc/dovecot/master-users
   driver = passwd-file
   master = yes
   pass = yes
}
passdb {
   args = /etc/dovecot/dovecot-sql.conf.ext
   driver = sql
}
plugin {
   deleted_to_trash_folder = Trash
   lazy_expunge = EXPUNGED/
   quota = maildir:User quota:ns=
   quota_warning = storage=98%% quota-warning 98 %n
   quota_warning2 = storage=95%% quota-warning 95 %n
   quota_warning3 = storage=92%% quota-warning 92 %n
   quota_warning4 = storage=90%% quota-warning 90 %n
   quota_warning5 = storage=85%% quota-warning 85 %n
   quota_warning6 = storage=80%% quota-warning 80 %n
   sieve = ~/.dovecot.sieve
   sieve_before = /var/mail/%n/sieve/vacation_message.sieve
   sieve_dir = ~/sieve
}
protocols = " imap sieve pop3"
service auth {
   unix_listener auth-userdb {
     group = vmail
     mode = 0600
     user = vmail
   }
}
service imap-login {
   inet_listener imap {
     port = 0
   }
}
service pop3-login {
   inet_listener pop3 {
     port = 0
   }
}
service quota-warning {
   executable = script /usr/local/bin/quota-warning.sh
   unix_listener quota-warning {
     user = vmail
   }
   user = vmail
}
ssl = required
ssl_cert = </etc/dovecot/ssl/certs/mail.home.example.com.crt
ssl_key = </etc/dovecot/ssl/private/mail.home.example.com.key
userdb {
   driver = prefetch
}
userdb {
   args = /etc/dovecot/dovecot-sql.conf.ext
   driver = sql
}
protocol lda {
   info_log_path = /var/log/dovecot/dovecot-lda.log
   log_path = /var/log/dovecot/dovecot-lda.log
   mail_plugins = quota sieve
}
protocol imap {
   imap_client_workarounds = delay-newmail
   mail_max_userip_connections = 100
   mail_plugins = quota imap_quota lazy_expunge deleted_to_trash
}
protocol pop3 {
   mail_plugins = quota lazy_expunge
   pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
   pop3_uidl_format = %08Xu%08Xv
   ssl_cert = </etc/dovecot/ssl/certs/pop3.home.example.com.crt
   ssl_key = </etc/dovecot/ssl/private/pop3.home.example.com.key
}

Any help will be much appreciated!

Thanks,
Bar.