[Samba] winbindd, AD and 'w'

[avk]

Good day

I've got a very strange problem with AD and winbindd.
What I'm trying to do is to let AD users to login into freebsd box
(using pam_winbindd).
I've joined domain successfully, everything works perfectly but
several users cannot login.

Login fails for ALL users who have 'w' in their samAccountNames, and
ONLY for them.

wbinfo -n swan gives:

 /usr/local/samba/bin/wbinfo -n swan
Could not lookup name swan

for users without 'w' in usernames everything works fine:
/usr/local/samba/bin/wbinfo -n migrat
S-1-5-21-XXXX User (1)

Any ideas?