keyboard not functioning

[Errol Sapir]

The strangest thing happened to me. I was typing an e-mail and all of a sudden 
there is no reaction from the keyboard. Nothing works. Not typing, no 
controls, nada. I know the problem isn't with the keyboard itself as I can 
type and operate the keyboard before entering Kubuntu. I can type my password, 
enter bios etc. Once the computer gets to my desktop after typing my password, 
all keyboard action stops. I can do anything with the mouse, open programs 
etc. but nothing with the keyboard. 
Had my computer been a laptop, I know there are function keys to do all sorts 
of things. On a non laptop, I don't know of anything that stops a keyboard 
functioning in Kubuntu. Just to double check myself I even replaced the 
keyboard with my wife's keyboard but there was no improvement.
Any suggestions where some command could change the situation back to normal?
TIA
Errol