Answer:
I have a LG tv that I had to turn the back-light above 70 to use a remote near it.
In order to use the remote with the back-light set at 20 for a dark room, all I needed was to lay a piece of paper over the IR receiver of the device that was not responding.
It blocks enough light to prevent false triggers of the detector, but the remote's true signal is plenty bright to penetrate the paper.
Maybe I just need a smiley-face sticker in the right spot to make me happy... :-)