My keyboard has recently stopped working on my 11.10 persistant live USB. It works at the login screen, but when I log in, any time I hit a key I just hear the error "pop" sound. This happens in all of my sessions (unity, gnome shell, and gnome classic). Also tried the on screen keyboard (on-board), which didnt work either. Neither does the computers hardware power button, except when you hold it for 5 seconds.
I doubt this has anything to do with it, but it the interest of complete information I'll tell you that just before the error started happening I installed "Mediaplayer GNOME Shell extension" https://github.com/eonpatapon/gnome-shell-extensions-mediaplayer
As soon as I refreshed gnome with "alt-f2 > r > enter" the keyboard stopped working. I immediately disabled the extension in gnome-tweak, but the keyboard still refused to work.