I have been using my macbook without problem in my home for several months. The other night it froze and when I rebooted the computer, airport no longer picked up our wireless network. We have not changed the router settings so it appears to be a problem with my computer. I am able to connect to the internet via an ethernet cord but no luck with the wireless. (I am able to connect to wireless on a closed network at another site.) Any ideas on how to resolved the problem would be much appreciated.