Samba login problem

hi everyone
i have a running samba server but i have a problem
when i try to login in my server from an old machice with an old
account i can't login but if i made a new account with the same name
on the same machine i login with no problem
my security is share level
can anyone help me pls

 

Any errors in your logs?

 

in the log.smbd
it says

smbd/password.c:authorise_login(865)
authorise_login: rejected invalid user nobody

for an existing acoount
if i made a new account with the same name
i can log in normaly
plese help

 

What''s in your smb.conf?

Is it possible that the passwords of the old accounts have expired?