800ccc0f TCP/IP connection problem

I am running a Dell laptop with XP on a network connected
to a Server running Small Business Server 2000.
The network runs OK and the ADSL broadband internet
connection is fine and I can send and collect emails in
Outlook.

The problem is that I cannot set up a newsgroup
connection to our ISP. It works OK on the server itself
but not on my workstation. Any attempt to connect
shows "The TCP/IP connection was unexpectedly terminated
by the server" followed by:
Configuration:
Account: news.easynet.co.uk
Server: news.easynet.co.uk
Protocol: NNTP
Port: 119
Secure(SSL): 0
Code: 800ccc0f

I have tried pinging the news server and it works ok.
Users on W2000 can connect OK .
Any ideas please?
Chris.