I get this error when I try to connect to my WiFi access point, when it worked fine with previous operating systems and works again if I downgrade. It also works with the router in my other house. I have tried disabling WPA, using static DHCP, changing the SSID etc but nothing works. It happens with both the official N800 beta and the N810 image on the N800. My router is a ZyXEL Prestige 660HW-61 (Telefonica branded).

I've written more about this and other bugs here

Bug report: https://bugs.maemo.org/show_bug.cgi?id=2464