Are you using DHCP on both networks? It should Just Work.

You should not have to set a fixed IP address to connect to the empeg unless you don't have a DHCP server on your home LAN. But since you're talking about using a router on your home LAN, then I assume it's the DHCP server.

Make sure that the empeg is configured to be DHCP, and it should then work on both your networks.

If for some reason, one of your networks is fixed and one of your networks is DHCP, then one of the tricks listed here covers that situation.

Also, you can use the @home and @work macros in Hijack if you want to switch the player's network configuration between the locations.