[Samba] Samba + LDAP = SLOW Help plesase

[Grey Karapetyan]

Hi Guys!
Samba suspiciously slow

i have:
CentOS 5.2 final
Samba 3.0.28-0.e15.8


LDAP server placed on anoter (not Samba) Server
In ldap container "ou=Users" about 5000 entries

When Windows client's connect to samba - Authentification process S.L.O.W.
(about 20-30 seconds).
When number entries less - performance grow (when 10 users -
authentification process go 1-2 seconds)

How i can tune up performance?

==========
smb.conf


[global]
        log file = /var/log/samba/samba.log.%m
        log level = 3
        domain logons = no
        domain master = no
        local master = no
        preferred master = no
        wins support = no
        dns proxy = no
        os level = 0
#       server setup ---
        netbios name = testsrv
        workgroup = TEST
        security = user
        passdb backend = ldapsam:ldap://x.x.x.x
        ldap admin dn = cn=Directory Manager
        ldap group suffix = ou=NTGroups
        ldap idmap suffix = ou=Idmap
        ldap suffix = dc=test
        ldap user suffix = ou=Users
#       print setup ---
        load printers = yes
        printing = cups
        printcap = cups
        use client driver = yes
[printers]
        comment = All Printers
        path = /var/spool/samba
        readonly = no
        browseable = no
        guest ok = yes
        writable = no
        printable = yes
[print$]
        comment = Printer Driver Download Area
        path = /etc/samba/drivers
        browseable = yes
        guest ok = yes
        read only = yes

================
/etc/ldap.conf

uri ldap://x.x.x.x
base    dc=test

binddn cn=Directory Manager
bindpw xxxx


#pam_password    exop
#pam_filter      objectclass=sambaSamAccount

nss_base_passwd ou=Users,dc=test
nss_base_shadow ou=Users,dc=test
nss_base_group ou=NTGroups,dc=test
ssl no