[Samba] Samba 3.0 and login problem

[Supoj Choachaicharoenkul]

Hello,
	I'm using Samba 3.0 + LDAP on Redhat Fedora Core 1, in each
morning many (Windows 98) users logon, some could logon very fast, but
the left got to wait about 40 secs and got "The domain password you
supplied not correct or access to your logon server has been denied"
and the users have to re-logon again, if success it will be so fast
but if fail, they have to wait more 40 secs. It has no pattern how
many times they have to re-try, sometime it takes more than ten time
of trying before able to logon.
	Any hint?

Supoj