Spaces in typing

As I type, spaces are inserted into words and sometimes the cursor just runs
to the right and a "morse code" chattering sound comes from the hard drive.
It oftens happens in the little search window at the bottom of the Start
menu. I've turned down the sensitiving of the keyboard and track pad and
also disabled tapping while typing.

This doesn't happen always but regularly, especially in chat.

Any suggestions

Here's an example: n ow i s th e t im e fo r