Those all sound like good ideas, but I'm using a desktop computer; don't even own a laptop anymore, and I've only got the one keyboard. And I'm not getting any indication of stuck keys anywhere else. Of course that's not to say that could not be the problem. Using the optical mouse, I can click on "Posts" for Search Type, then tab to keyword(s) and type in the search word or string, but if I use the mouse to click on the box for the keyword; no go. The cursor only shows there as long as I hold the button down on the mouse. And I've been unable to get to the Find Posts "Any Date", but a few minutes ago, that worked. It's worked today twice out of probably 15 attempts.
But I'm not having any problem with anything else on TBN, or on any other website.