Disk usage roundcube Dovecot

[Captain]

Hello!

I have ISPConfig 3, Ubuntu 12.04, Dovecot, Sieve, roundcube.
I configure imap quota plugin.

It is work fine with default folders (Inbox, Sent, Draft, Junk, Trash)
I import new folders from another email server.
Do chown for vmail.
But it is does not work for new folders.
Disk usage not calculated for new folders.

Dovecot.conf

protocols = imap pop3
auth_mechanisms = plain login
disable_plaintext_auth = no
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_privileged_group = vmail
ssl_cert = </etc/postfix/smtpd.cert
ssl_key = </etc/postfix/smtpd.key
passdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}
userdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}
plugin {
  quota = dict:user::file:/var/vmail/%d/%n/.quotausage
  sieve=/var/vmail/%d/%n/.sieve
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  unix_listener auth-userdb {
    group = vmail
    mode = 0600
    user = vmail
  }
  user = root
}
protocol imap {
  mail_plugins = quota imap_quota
}
protocol pop3 {
  pop3_uidl_format = %08Xu%08Xv
  mail_plugins = quota
}
protocol lda {
  mail_plugins = sieve quota
}

namespace private {
  prefix = INBOX.
  separator = .
  inbox = yes
}

plugin {
  quota = maildir
}

How to solve this problem?

Thank you.