I have a nokia n800 (not flashed to diablo - yet), and I am experiencing some problems with it.
Yesterday my internet was working perfectly fine. I left it on standby during the night and put it on "offline" mode. When I went back to online mode the next day, the list of available routers showed up, but when I tried to connect to mine, it would not work. It also would not work for other routers.
I tried to go back to offline and online again. I tried shutting it off and turning it back on, but none of those seem to work. Maybe if I reflash to diablo I can get it working again ....
Can you confirm that the router is working correctly? Perhaps another wireless device that you can connect. If not, turn off and let the router sit for 60 seconds and restart it. It might be that the router has crashed and needs to be rebooted.
So.. you can see access points but can not connect? Is there any error message the N800 show you? Can you tell if N800 did register with the Access Point? (Log in to the access point from another computer and check the clients table.)
You might try real hard reset by shutting down the N800 and removing battery for couple minutes... if that doesn't work then as last resort you may try reflashing the OS. If that doesn't help... then maybe it is hardware problem and needs to be sent for repair.
Okay .. now I'm starting to think its my router. I tried it again on my neighbors connection (shh), and it worked. I'm going to try to reset the router and see if that works.