I've got w2k3 server and xppro clients, certified cat6 network working @100mbps, cisco switches, all the stuff. And got the same problem. When I upload file from client to server, it goes fine, network load is up to 70%, 6-8 mbytes/sec. But when I download file from server, it works out like 1-2% load, and 200-300 kbytes/sec speed. Whatever I tried didn't solve the problem. P.S. server is intel se1325tp1e and clients are intel 865 perlx.