Yesterday after setting up my wireless router I noticed that my MacBook was getting really miserable reception. I couldn't figure it out, especially as a Vista machine was getting fabulous reception in the same place. Even my iPhone was screaming along at previously unseen speeds, but my MacBook continued to lose connection every few seconds, and would take minutes to load (or sometimes refuse to load at all) simple pages.
Confounding the issue was the fact that I was receiving four bars of wireless strength, and that it was a private network with little usage. Quite confused, I plugged it directly into the wireless hub, and once again pages loaded quickly.
Looking through the hodgepodge of suggestions, I found the key that lead to my solution. For whatever reason, the AirPort Extremes on these defective machines are having issues with the WPA encryption algorithm. Apparently many people were having success by disabling all encryption, but I tried going the other route and enabling WPA2 encryption on the router, and the connection is now working perfectly.
I'm pretty bewildered about what went wrong at a software level, and many people are complaining that these problems emerged after upgrading to Leopard, which is when mine emerged as well (suggesting that it is not merely a hardware issue). What I will say, is that I think we'll need to rethink wireless technology, as there are thirteen wireless networks detectable on iStumbler from my living room table. Six of them on channel 6, four on channel 11, two on chanel 1, and there is actually one claiming to be on channel 9 as well.
Wireless network congestion will be the traffic congestion of our lives.