Windows Vista attempts to dial out with modem when using Ethernet/Wi-Fi

We have a computer that uses both Wi-Fi at home and a dial-up weird thingy on an air-card from Verizon while away.
The problem is, when ever you're using the Wi-Fi, and something, ANYTHING on the page doesn't load first try (Server times out, what ever...), Windows prompts the user to select a dial-up connection to use.
Is there a way to prevent it from doing this? I can't remember how to tell it to disable or not use the connection temporarily or at least while the Wi-Fi is active...

in your browser, Tools->Internet Options->Connections

Click Never dial a connection

check all installed software including drivers and application assistance such as Java. Much of it is set up to automatically install updates, and this will start to dial out if the internet connection is also set to automatically connect if something requests it. Software usually has a place to prevent automatic updates, but it can be a trial to find it ! In fact I suspect Adobe Reader has the confounded cheek to check for updates without permission, or any way to deny permission....