Lose ability to get on/off line (via dial up) using wireless card

My wife and I have a Linksys wireless network set up. Unfortunately, we
share a lowly dial-up connection. My wife's PC is the one connected to the
phone line, but I can also control the dial-up session through an Internet
Conncection Sharing icon.

When I go to Starbucks to use the T-Mobile network, I have to (obviously)
change network configuration--and then change it back when I come back home.
However, when I come back home and re-configure the network, I lose the
ability to start and stop a dial-up session. This has happened before, but
the ability eventulaly comes back. It's been 3 days now, and I still don't
have the ability to turn on/off a dial-up session. Can anyone help?

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remove "smooth" from my yahoo.com address.

hmc