Adding a wireless device to a 1 port cable modem ad 4 port router setup

At least twice, I have tried to add a wireless device such as a print server to an already existing wireless connection. But the linksys print server device is not seeing the wireless network. I have the correct SSID, WEP key phrase.. Print server device of course sees network when I use an eternet cable in between PS and router. Does anyone have anythig on this? DO I need to change to static IP on the ps and change its gateway?