[Samba] machine add error to samba PDC

[Pavan]

Hi All,
 
    I have setup my samba as a PDC and testparm gives me the right
result, but when I am trying to add my XP client to SAMBA I receive an
error as "Logon failure: bad username or password" or "Username could
not be found". I am using root as the domain administrator and have
added root account using smbpasswd and can see it using pdbedit -Lv. I
can logon successfully from my windows client from run and typing
"\\servername <file:///\\servername> ".
 
Why do it complain when I am adding the machine that It cannot find the
user??? Backend is simple smbpasswd file.
 
Anyhelp is greatly appreciated.
 
Thanks,
Pavan.