This sounds exactly like the setup that Mark Lord helped me do last year. I have a WRT54G wireless router connected to my cable modem, VOIP phone, a color laser printer, a couple of computers, etc. Another WRT54G on the deck downstairs picks up the signal from my primary router and rebroadcasts it to the floor below. It has worked perfectly, totally trouble-free for more than a year now.

tanstaafl.