Bruce,
Are you using a router or connecting directly to another computer that has a wireless card? The second is called an "ad hoc" network and works well but is a little trickier to set up, e.g., you have to tell XP that this connection, which you name in XP and in SB3's setup, is an adhoc/computer to computer connection. You can google "setting up an ad hoc network" and find instructions, but essentially under "view wireless networks" when you right click the connection, then "change the order of wireless...", and then "advanced" you indicate that you want to use ad hoc connections.
After you enter the name in the SB3 setup and with the power on, you then connect the computer to the network, and then the sb3. Hope this helps.