From the strange but true category, if the push buttons on a newer Nautel become less responsive (or non-responsive), take a push pin and poke a hole in the membrane that covers each switch. Nautel explains that there is air in there that loses it's effectiveness and the hole allows fresh air. If I read this on April 1, I'd ignore it. But I did it and it worked quite well. Add a push pin to your tool kit if you have a Nautel!