Do yourself a favor and buy Roadshow. It comes with a script for the xsurf 100. You basically install it, move the config over as the docs say and reboot.
As for Poseidon be sure you arw using version 4.5 and launch prefs. Tou need to also open a cli and type the command to attach the ports as mentioned in the docs, save the config in prefs and reboot. The dot next to online should be green.