Connecting to non-preferred network/cannot see "all availablenetworks" and choose which is preferred.

I'm running XP and connecting through an Orinoco card to a wireless network.
I do NOT use WAP encryption.

With the growth of wireless my apartment has come into range of several
networks, and my XP machine sometimes connects to the wrong network (which
gets me on the 'Net but doesn't allow me to see my printer).

When I try to select the preferred network using "Available Networks", that
screen remains grayed out-- I cannot see the available networks.

All of this time, however, I remain connected to one (if not my preferred)
network and able to get on the Net.

Any suggestions?

My objective is of course to make sure I stay connected to my preferred
network.

Thanks much

Dt