I'm not sure if it's worthwhile to pursue, but the doorking model I have at home has an ethernet port, if your facilities permit, you could connect over that instead of over the modem. (I don't know how terrible their IP stack is though; I don't have enough pairs going to the device)
Also: they're kind of overpriced in my opinion, but you can still buy USB based hardware modems, which would allow you to move this to a newer computer if needed, without having to worry about modem drivers.
Also: they're kind of overpriced in my opinion, but you can still buy USB based hardware modems, which would allow you to move this to a newer computer if needed, without having to worry about modem drivers.