Error Adding XP Pro machines to our Windows 2000 Server

[Cerran]

I've been having fits the past couple days adding some machines to our office windows 2000 server domain. Every time I try to join the domain I get the following error:

The following error occurred attempting to join the
domain "domain name". The network name cannot be found.

It's driving me nuts. I am getting leased a IP by the 2000 DNS server and I can access the internet on both machines. I just can't seem to find a solution to the problem. I've look just about everywhere.

WINS is operating
Netbios of TCP/IP is enabled, but when I browse the network I cannot see the server.

Suggestions?

 

[Cerran]

Fixed! Turned out one of our users had an insecure password and someone hacked in and dropped a backdoor trojan on the server. We will be buying a firewall for the server today to prevent this again and making sure everyone has a secure password.