I have an odd problem. i was trying to use my new macbook in a friends flat. She has a Wifi system. It works fine with her older macbook. It works fine on my Iphone. My macbook can't see that there is a network at all, tho it can puck up her neighbours networks. The little bars remain blank, and the network is not listed in those a viable to join. It works fine with my own network at home. Until recently my macbook pro worked in her flat, and stopped. i can't be sure but the stop may have coincided with my upgrading to snow Leopard, which my new macbook also uses. Is there a problem with Snow Leopard? It there some work round?