Ajuda SSH + Autenticando em AD 2008

Srs,

Fiz a configuração para uso do AD para autenticar meus usuários via SSH..

Está funcionando legal, autenticando, tudo OK, porém, no log do secure eu tenho essas mensagens e gostaria de entender por que tenho alguns failed... se alguem puder me ajudar :)

Feb 2 11:31:41 server01 sshd[21412]: pam_krb5[21412]: authentication fails for 'my_user' ([email protected]): Authentication failure (Cannot read password)
Feb 2 11:31:41 server01 sshd[21412]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=192.168.1.1 user=my_user
Feb 2 11:31:41 server01 sshd[21412]: pam_krb5[21412]: error guessing name of local host principal
Feb 2 11:31:41 server01 sshd[21412]: pam_krb5[21412]: TGT failed verification using keytab: Hostname cannot be canonicalized
Feb 2 11:31:41 server01 sshd[21412]: pam_krb5[21412]: authentication fails for 'my_user' ([email protected]): Authentication failure (Success)
Feb 2 11:31:41 server01 sshd[21412]: pam_winbind(sshd:auth): getting password (0x00000010)
Feb 2 11:31:41 server01 sshd[21412]: pam_winbind(sshd:auth): pam_get_item returned a password
Feb 2 11:31:41 server01 sshd[21412]: pam_winbind(sshd:auth): user 'my_user' granted access
Feb 2 11:31:42 server01 sshd[21412]: pam_winbind(sshd:account): user 'my_user' granted access
Feb 2 11:31:42 server01 sshd[21412]: Accepted password for my_user from 192.168.1.1 port 58368 ssh2
Feb 2 11:31:42 server01 sshd[21412]: pam_unix(sshd:session): session opened for user my_user by (uid=0)

Obrigado