[Dovecot] sieve and fileinto encoding

[proton-sss]

Hello All!
I`m using dovecot 1.2.6
I have folder named in russian "САПП", and when in filter i wrote:
     fileinto "САПП";
all works well.

Now i find 2 web applications to manage sieve filters (horde-ingo and 
squirrelmail/avelsieve) - then creates filter like this:
if header :contains "Subject" "САПП"
{
fileinto  "&BCEEEAQfBB8-";
stop;
}

And creates another folder ".&-BCEEEAQfBB8-", but GOOD folder name 
already exist ".&BCEEEAQfBB8-".

Please help to understand why dovecots deliver make this happen.

Best regards
Michael

p.s.
dovecot -n
# 1.2.6: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.28-hardened-r9 i686 Gentoo Base System release 1.12.11.1 
reiserfs
log_path: /var/log/dovecot_err.log
info_log_path: /var/log/dovecot_info.log
protocols: imap pop3 imaps pop3s managesieve
ssl_cert_file: /etc/dovecot/ssl/mail.proton-sss.ru.pem
ssl_key_file: /etc/dovecot/ssl/mail.proton-sss.ru.key
disable_plaintext_auth: no
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
login_executable(managesieve): /usr/libexec/dovecot/managesieve-login
mail_location: maildir:/home/%u/.maildir
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_executable(managesieve): /usr/libexec/dovecot/managesieve
mail_plugins(default): acl imap_acl
mail_plugins(imap): acl imap_acl
mail_plugins(pop3):
mail_plugins(managesieve):
mail_plugin_dir(default): /usr/lib/dovecot/imap
mail_plugin_dir(imap): /usr/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/pop3
mail_plugin_dir(managesieve): /usr/lib/dovecot/managesieve
namespace:
   type: private
   separator: /
   inbox: yes
   list: yes
   subscriptions: yes
namespace:
   type: shared
   separator: /
   prefix: shared/%%u/
   location: maildir:%%h/.maildir/:INDEX=%h/.maildir/shared/%%u
   list: children
   subscriptions: yes
lda:
   postmaster_address: postmaster at example.com
   mail_plugins: acl sieve
   mail_plugin_dir: /usr/lib/dovecot/lda
   log_path: /var/log/dovecot_deliver.log
auth default:
   mechanisms: plain login
   passdb:
     driver: ldap
     args: /etc/dovecot/dovecot-ldap.conf
   userdb:
     driver: ldap
     args: /etc/dovecot/dovecot-ldap.conf
   socket:
     type: listen
     client:
       path: /var/run/dovecot/auth-client
       mode: 432
       group: mail
     master:
       path: /var/run/dovecot/auth-master
       mode: 432
       user: mail
       group: users
plugin:
   acl: vfile
   acl_shared_dict: file:/var/lib/dovecot/shared-mailboxes
   sieve: %h/.dovecot.sieve
   sieve_dir: %h/sieve
dict:
   expire: db:/var/lib/dovecot/expire.db