samba - Mar 2014 - Samba4 DC does not claim master browser role

hi all

i have some problem with my samba 4 installation, lately my samba 4 DC does
not claim master browser role, so the role is taken by other pc client,

is it a bugs in samba 4 ?

here is my smb.conf

[global]
        workgroup = DOMAIN
        realm = DOMAIN.co.id
        netbios name = PDC
        server role = active directory domain controller
        idmap_ldb:use rfc2307 = yes
        dns forwarder = 172.16.99.1
        vfs objects = acl_xattr
        map acl inherit = Yes
        store dos attributes = Yes

# Disable Printing Support
        printing = bsd
        printcap name = /dev/null

        map to guest = Bad User
        security = user

        name resolve order = wins, host, bcast
        allow trusted domains = yes
        domain master = yes
        domain logons = yes
        wins support = yes
        interfaces = lo eth0
        bind interfaces only = yes
        local master = yes
        preferred master = yes
        os level = 35

        log file = /var/log/samba/%m.log
        log level = 4






-- 

Thx & Warm regards
Zhia Chandra