It's the TV. You can get the same response by pressing and holding the mute button on the TV's remote. I thought there was a way to disable the shortcut in the TV's menus, but I just looked through mine and couldn't find anything. I've gotten into the habit of making sure I barely touch the mute button when I use it. I don't know if trying a different code for Samsung when setting up the remote for TV control would help, but it might be worth experimenting with if/when it really bothers you.
Thanks. That helps and as I could test, pressing the button for more than a second will bring the screen. I'll just press it quickly. Not a problem.
