Networking 3 computers 1 with xp and 2 98se + internet?

I had everything working fine until I added broadband internet to the Primary machine running xp. Now Internet works fine on all 3 computers, the other 2 computers on 98se can share folders with each other, but not with the xp machine nor xp machine with them. I have 2 nic cards one for internet and other for local network. It looks like ip #'s match up...sugestions????????