If you're going to try to test it "live" you'll need to go into the setup on the 2nd device and set the IP address to something different than the one by the modem. You also need to set DHCP to DISABLE.
Um, I am just connecting a Linksys WRT54GL router to the cable modem (power cycled too) and see if an old MacBook Pro can connect wirelessly to it in various areas of the house.
·