[Samba] strange auth issue

[Sonic]

On Tue, Feb 21, 2017 at 6:22 AM, Rowland Penny via samba
<samba at lists.samba.org> wrote:
> Except the OP was logging into a windows computer and the Samba DC has
> 'map untrusted to domain' set to 'No' by default.

Correct. And I am not overriding the default. Testparm displays "map
untrusted to domain = No".

> I think it is a windows thing, though I couldn't see anything in the
> event logs when I tried logging in with a mixed-up DOMAIN name.

Were able to recreate this?
The client system was a 'fresh' (new, out the box), Windows 7, that
was then fully patched, then joined to the domain just previous to my
fat fingered logon attempt (that was surprisingly successful).

Chris