I don't understand much about networking but I had problems setting up my home LAN of 4 computers with either XP or 98 and a hub. To tell you the truth seems like win came up with a new problem every time I tried adding this or removing that...
In the end I came to the conclussion that if the hardware is OK than its best to manualy assign ip address to each computer, a mask and a gateway for sharing internet. saved a lot of time.
also use "winipcfg" to see everything works and ping from one computer to the other.
BTW setting win98 network was easier