[Samba] I got some problem with samba 4 installation

[Mangapuli Roy]

hi guys,

I got some problem with samba 4 installation. I have finish the 
installation.
when I tried to client join from XP for the 1st time, I have no problem 
but when I disjoin the client
and after that join again show message error "logon failure : unknown 
username or bad password "
while in the first time i joint the client had no problem.
for your notice, I join the with user administrator and pass 123456

is there any of you could help me guys
thanks.

Best Regards,

Roy