Using XP and MS Word, on a dell computer.
Several times a day I will have this problem. I am typing and suddenly the last digit typed will repeat, continuously. It will go on and on and on, until I do something to stop it. If I right click my mouse, it will pause. If I try to type again, the digit will repeat for line after line.

First, I assumed I had keyboard problem, so I switched keyboards. The same problem exists. I changed the mouse and the problem exists.

When it last occurred, I was able to stop it with rt clicking, followed by resumption of the problem when I tried to do any typing. This happened 12 or 12 times. Finally, I rt clicked (which paused the repeating) and did a ctrl-alt-delete and was able to start typing, again.

It is not the keyboard, because I switched keyboards.
It is not the mouse, because I switched my mouse.
I have not excluded the Belkin kvm switch, which I will do next, by connecting the keyboard directly to the computer.

Any idea what could be causing this problem?