Ok.
I've taken the modem out of the server. I think that the suggestion of using it as solely a file/network/printer server is excellent as is using the XP as the gateway.
I've stuck a modem into the Mandrake box just for the hell of it and because pretty much no viruses affect Linux. I guess that means I'll have to fix it up with an antivirus of some variety just to be on the safe side.
Since somebody said I can use 2 NICs or 1 NIC and a modem and I have 2 NICs in the server, that means that I don't need a switch or a hub? I don't envisage 2PCs and a laptop all sharing the server simulteneously. If that happens then the quantity of data being transferred might be low enough just to slip a hub into the setup temprorarily.
I'll have a look at the manual and see if there're any instructions on how to configure for 2 NICs and no modem on the SME box.
My first task is to get the Mandrake box working. My next task is to get the SME box configured as a file-server/server. After that I'll worry about printer sharing. Then I'll worry about routing data traffic via the server and the XP box to the Internet.
MP