from Amazon, or check out the AirPort “Connection Timeout” issue | January 4, 2008
It seems there is a glitch in the AirPort connection dialog (or underling software) in Leopard that will occasionally prevent you from connecting to a wireless access point with a “Connection Timeout” message (usually involving WEP, which is yet another reason to upgrade to WPA). While frustrating, if you find yourself in this situation there is a solution: open up Safari and click your way through the the Network Diagnostics Utility (a button to launch this appears when you launch Safari and it can’t connect to the internet). This will successfully allow you to connect to the wireless access point (provided something else isn’t wrong anyway). As usual, I’d assume that there will be permanent fix for this soon, but at least for now there is a work around.