You might need to go to "open network preferences" and click on "network name:" your network should be on that list. Sometimes the Airport will pick up and join 5-10 different networks, but it's important that you select your known network to join, then click "advanced" and you can see "preferred networks" and yours should be listed, and I always click the box "remember any network this computer has joined." You should be good to go. 😎