I upgraded the OS on my N800 and suddenly my home (AirPort Extreme Base Station) network with WPA/WPA2 encryption disappeared. After reading here I tried to switch the encryption off, and voilá - my home network reappeared, but then I lost contact with my Air Port Express (speakers). I switched the encryption back on, but this time to WPA2 only and now everything works fine - except that my stupid IBM ThinkPad will not connect. Back to square 1.