As it seems, there are dozens of other users who experienced a connection timeout using AirPort W-LAN connections on Macs. There are dozens of different solutions described in the forums, I tried plenty of them. From reboot to deleting the WPA2 key from the keyring, nothing worked. Eventually I tried the following and this worked for me. (Note that I’m using a German installation, the real English translation may be slightly different.) Go to Mac (the Apple symbol in the top left) -> Location -> Network Settings Click on the “Airport” entry on the left Click on the “additional options” button On the Airport tab, click the “+” button below the “preferred networks” list Click on the “show networks” button and select your W-LAN from the list Enter your password That way, I could connect without problems. It may be coincidence that exactly this way worked, and none else, but maybe there’s really some strange difference. Let me know if this helps.
…it just works! (Source)