problems with file's ownership

[Andrea Avi]

I need help...

I have samba 2.0.4b on solaris7 acting as a PDC

>From NT4.0 workstation I can logon into samba PDC as a samba user
(in /usr/local/samba/private/smbpasswd) and it work fine.

The problem is that when a user create a file on a NTFS partition (on
the local workstation)
the ownership of this file is "Account Unknown"

I did not find any answer in the FAQs neither in the NT-dom mailing list

Probably my smb.conf is miscounfigured or I forgot some simple entry...

in my smb.conf I have

security = user
encrypt password = true
nt acl support = true
guest access = no
guest account = nobody

If somebody had the same problem and resolved it...
please help me