How to delete a "preferred" network

Hello,
     if I'm right, when I successfully connect to a network, that network is automatically added to the preferred network list (it will show a yellow star), and the software will automatically try to connect to it when it is available. Is there a way to remove an unwanted network from that list, so that it will not be used in the future? If I remove it from the Windows Mobile network manager, WiFi Monster readds it the next time it is used.
     Thanks in advance for your help.