[Samba] Cannot connect from Vista, error 67 The network name cannot be found

[osp at aloha.com]

I have a server which will accept a file sharing connection from a FreeBSD
workstation using smbclient, but not from a Vista workstation. The server
also performs as a NAT gateway. Upstream network configuration is by DHCP
(dhclient), the downstream side is assigned 10.0.1.0. All Samba clients
will be on the downstream side. The NAT portion is working fine. By design
the Vista clients will be members of domains which have nothing to do with
this internal network, or each other. Assume client users do not have
elevated privileges and that Vista is highly locked down by GPO. Network
connections to servers in the domain are allowed.

Currently the printer sharing is not working because CUPS has not be set
up. This should be irrelevant to this issue.

I did not see anything useful with debug levels less than three, and even
at three I cannot determine the problem. Hopefully someone here can. Sorry
about the long post.

Server OS: FreeBSD 8.0
Samba version: 3.3.7 (installed from ports)
Hostname: g8dr01
There is a user account g8team. 
Home folder is /home/g8team, owner and group are g8team.
Home folder permissions are 755.
There is a folder /winclr, owner and group are g8team, permissions 755.
This is a separate partition.