[Samba] unstable winbind

[Miguel Angel Jinez]

Hello everybody
I am trying samba with winbind to user trusted domain.
I have seen that winbind`s work is unstable, by moments when I perform

winbind -a domain\\user%passwd  #the response is:
plaintext password authentication succeeded
challenge/response password authentication succeeded

and a time after:

winbind -a domain\\user%passwd  #the response is:
plaintext password authentication failed
Could not authenticate user intertur\t68 with plaintext password
challenge/response password authentication failed
error code was NT_STATUS_NO_LOGON_SERVERS (0xc000005e)
error messsage was: No logon servers

What can I configfure to make it stable?

Miguel Jínez