Generals slow speed on LAN

[Guest secontek]

I have 2 identical machines:Barton 2500+,Abit NF-7,512 mb Ram,Radeon 9600Pro.The games(both Generals and Zero Hour)runs just fine in single player,but on TCP/IP the game is very fragmented,with the scrolling still perfect,so it's not a graphic card issue. Other games runs ok,except for Porsche Unleashed,with the same chopped gameplay--good FPS inbetween the "cuts"(IP-peer to peer).

Thanks in advance for your help.