Login loses first character

I have a new install of Kubuntu and a minor problem with the login screen. My user name is displayed by default when the screen appears. The cursor is blinking in the password field. When I begin to type the first character is not recorded. In order for the login to work I have to first type a space or type the first character twice. Is this unusual? I have been using various Linux distros since Red Hat 8 and this is the first time I have encountered this sort of problem. I hope this is not a "feature" because it is annoying.

Do you have multiple mouses?

I had this problem too.   I had 2 mouses installed  a ps/2 mouse as well as a USB.   Removed ps/2 mouse, and it started accepting everything I typed the first time I typed.