Windows 2000 server cannot access Internet

I have a Windows 2000 server which cannot access the Internet using TCP
using FTP, IE, or automatic updates. The server establishes the connection,
then receives an "HTTP Continuation or non-HTTP traffic" packet, then the
server sends a packet with the TCP window set to 0 bytes. Following this,
the remote sends TCP keepalive packets with the server responding with TCP
zero window packets. Does anybody have any idea how to fix this? I have done
some searching on Goole and have not been able to find a solution yet.

Thanks in advance,

Mike Donovan
(E-Mail Removed)