Proxy setting

I have Nt server 4.0 with 10 NT workstations including one 98. My win98 pc is also functioning as proxyserver (win proxy 1.4)because of modem problem on the NT. The speed of my ISP is 33 bps with my modem 56k single chip(conexant).On the network i open the same site on more than two pc’s. It does not because of restriction (can not use more than two users.) Tell me what is the problem. How can i cover the situation.
OK