Network problem

We had 2 computers running GP4 on a LAN game, we race 1 lap and then the game crashes.
This happens every time.
I have tried win98 and winxp on the machine that crash, with the same result.
The other machine just hangs in the game.
We have tried different hardware as well.

I have tried IPX and TCP/IP, with patch and without.

Have anyone seen this problem?

please help.........



P4 2.53
512MB ddr ram
Aopen GF4 TI 4200 128mb DDR
SBaudigy sound