I get proper behavior when I do a mount -t cifs //foobar/share /mnt/tmp -o user=username with v3.0.33, v3.3.12, but not with v3.5.4. With this latest version I get This type of error: Sep 9 21:35:16 foobar kernel: Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE Sep 9 21:35:16 foobar kernel: CIFS VFS: Send error in SessSetup = -13