Rated 5 out of 5 stars

Plz check my Update1 comment in my earlier post on my calculator request.

Also, as noted by another user, I also faced the same issue of keypress. If the cursor is not in any active element i.e., if the page is in focus & not any text boxes, any key press is being redirected to the search box; because of which, instead of executing the command meant for that keypress, the search box is being filled with the text.
I use Augopager as well as Mouseless Browsing, which sometimes depend on the command given while no text element is active. For instance, in Autopager, to add a new rule, user needs to select document objects and in order to select a link or the data-content-scope, there are few simple DOM tools like widening or narrowing the DOM scope by pressing "W" & "N" respectively & finally selecting by pressing "S". So, if Fastest Search is installed, this is not happening & instead, W or N or S is getting typed in the search box.
This is not happening if Fastest Search is not installed as I tested. Please look into this.

This review is for a previous version of the add-on (1.51).  This user has other reviews of this add-on.

That's part of a feature I put in, I can set an option to allow you get rid of it. UPDATE: download v1.60 through "Versions" at bottom of addon page, and in "Misc. Settings" panel, uncheck 'Focus in searchbar when not FAYT'. That's it.