Can't browse W2k3 DC from systems in Trusted/Trusting NT Domain

We are unable to browse server resources by running
Start/Run: \\<servername> or \\<servername.domain.com>
from systems in a trusted/trusting NT domain with respect
to one and only one of our branch W2k3 Domain Controllers
which is also a file/print server. This is the error msg:

\\<servername> dialog box with red "x":

"There are currently no logon servers to service the logon
request."

When doing Start/Run: \\<servername> from systems in the
trusted/trusting NT domain to any other domain controller
in AD domain, there is no problem displaying server
resources. We are running Domain Dfs in the AD domain and
the ability to resolve the UNC server name is critical.

We can ping the problematic server by name and fqdn from
the trusted/trusting NT domain.

When attempt to Start/Run: \\<servername> from XP Pro
client in trusted NT domain, get Windows Explorer error:

\\<servername> is not accessible. you might not have
permission to use this network resource. Contact the
administrator of this server to find out if you have
access permissions. There are currently no logon servers
available to service the logon request.

However, from the same XP Pro system we are able to
Start/Run: \\<anyotherservername> in the AD domain without
a problem.

There are 5719 netlogon errors in System event log on the
problematic branch office domain controller occurring
daily. Server reboot doesn't resolve the issue.

The problematic server has correct A and NS records in DNS
and also correct entries in WINS. It is running DNS but
not WINS. It is a global catalog server. Each domain is
running WINS but the WINS is not yet replicating inter-
domain. However, the fact that WINS is not yet replicating
inter-domain has not prevented access to server resources
from the trusted/trusting NT domain to any other server in
the AD domain.

There was a 2 way external trust recently created between
our NT domain and AD domain. The dcdiag /v /e /c is
completely normal and all of the sites and site links in
AD Sites & Services are correctly established with auto-
generated connection objects correctly in place between
the bridgehead server at the hub site and the branch
office Domain Controllers.

I'm also cross-posting to Active_Directory.