After disconnect Bluetooth keyboard, onscreen keyboard doesn't appear?
 

Has anyone else had this issue where if you use a bluetooth keyboard for a bit and then disconnect to return to using the built in text entry (n800), nothing comes up?

Re: After disconnect Bluetooth keyboard, onscreen keyboard doesn't appear?
 

Yes, same here.

Re connect the bluetooth keyboard, then disconnect it from the tablet, not by shutting the keyboard off. Hope it works for you :)