Replying to Richard since the original poster is posting from a spam haven
usenet provider that is dropped by my news server.
If this is a work computer, check with your network administrators. If
this is a home computer, check with your ISP.
Actually, that's not quite accurate. The original poster might try putting
their FTP client in "passive mode." The default active mode does not work
through most NATs (Linux-box based NAT router setups with connection
tracking enabled being the notable exception). In the typical active mode
connection, the client connects to the FTP server, then the FTP server
connects back to the client. If you don't accept outside connections,
active mode will also fail.
Passive mode uses the single, client-initiated connection for all
communication. You lose the ability to cancel a file transfer without
dropping the connection in favor of being able to connect through NAT
routers that don't track connections and firewalls.