Reset airport to default.

http://support.apple.com/kb/HT3728

 

Well, your AirPort settings on your MacBook are dependent on what network you're joining. You can remove a network and add it again, to start over. It's probably simpler to just correct whatever you need to. What's messed up? You can also click "Assist me..." then use Diagnostics or Assistant:

​

 

System Preferences > Network > Airport > Advanced > Click on the network name you want to start over with > Click the little minus (-) symbol underneath the network list to forget it.

Then you're starting over with a fresh connection to that network.

 

I know what you mean, I just bought this Macbook and Apple F***ed OSX since I last had it when Tiger was around. Everything is fine except for the F****ing airport that keeps disconnecting at random intervals. To make things worse now the stupid machine won't join the network because the airport keeps self assigning its own ip and will randomly join when it gets one from my provider. For all the talk that Windows sucked I hadn't had a problem this stupid on my HP.

 

1. Turn off AirPort
2. Macintosh HD>Library>Preferences>SystemConfiguration
3. Delete com.apple.airport.preferences.plist
4. Restart.

That will discard any current AirPort settings and once you restart, everything should be in it's default state.

 

I called Apple and they told me this solution and still had some problems, but for some reason I tried it to replicate it with Camino. Well I've been running 4 hours problem free with Camino, so long Safari!