NT Authentication with Named Instances

Hello FreeTDS enthusiasts! I first would like to say that I love FreeTDS and
the great connectivity it brings. I have a question for you all today, that
I have been having a hard time with lately. I have a SQL Server 2000 server
that I need to connect to via Linux FreeTDS. The server is in NT
Authentication mode only, and is using a named instance on port 4433. The
sql server is not connected to a domain, and can't be. The account I am
using to login is a local user on the server. Unfortunately, I cannot have
anything changed on the server, so I'm trying to work with what I have been
given. I am trying to connect using Perl's DBI:ODBC connection. For
reference, here is my DSN, (substituted localhost for real ip)

my $host = '127.0.0.1\InstanceName';
my $usr = 'HostName\UserName';
my $pw = 'Password';
my $dsn =
DRIVER=/usr/local/lib/libtdsodbc.so;SERVER=$host;PORT=4433;DATABASE=DataBase;UID=$usr;PW=$pw;TDS_Version=8.0";
my $dbh = DBI->connect('DBI:ODBC:'.$dsn) || die $DBI::errstr;

I keep getting the error, "Login failed for user '(null)'. Reason: Not
associated with a trusted SQL Server connection." I read the guide talking
about this, http://www.freetds.org/userguide/domains.htm, but the server is
set at "Send LM & NTLM - use NTLMv2 session secuiryt if negotiated". Here
are my conf files.

*odbc.ini*
[ODBC Data Sources]
VOIP
[VOIP]
Driver = FreeTDS
Description = Connection to the new voip DB
Trace = No
Server = 127.0.0.1
Port = 4433
Database = databasename
[Default]
Driver = FreeTDS

*freetds.conf*
[VOIP]
host = 127.0.0.1
instance = CRSSQL
port = 4433
client charset = UTF-8
tds version = 8.0

*odbcinst.ini*
[FreeTDS]
Description = FreeTDS Driver
Driver = /usr/local/lib/libtdsodbc.so


I can connect remotely by creating a user on my local windows maching that
matches the sql server user, and using Microsoft's Sql Server Management
Studio. I am hoping someone can help me, as I have run clean out of ideas.
My Google-fu seems to have failed me so far on this one.