Lazy response to keyboard

I I have suddenly begun having problems between my keyboard and keystroke response on internet sites. My site will display on the screen but when I try to type in my password, for example, nothing happens. I have to wait a few minutes in some cases before the site will accept keyboard strokes. This can become very irritating, especially when I am attempting to use search engines.

I I thought it was a bad keyboard, so I replaced the keyboard--no change.

This has not been a problem in the past, so I wonder what I am doing differently?