my macbook has been working fine up until yesterday when for no reason, the wireless stopped working. in airport, it shows that i am connected to a network and the strength is even high. but when i open firefox, safari, etc, it says that i am not connected to the internet. if it matters, i installed the automatic apple updates a few days ago and that may be related. i've already tried looking on apple's website for support and even resetting the airport preferences.plist but that didn't work. any help would be appreciated, thanks.