Hello Philhu. Since the situation requires us to use the IR remote, there may be some things that have been overlooked. I assume that placement of the second STB to another location that would move it out of line of sight is not possible. Your foil solution is effective, but there are some other things to think about. Maybe the signal is bouncing off a mirror, reflective picture frame or glass surface somewhere which is more easily moved. This can happen - when I was teaching a class once, my co-instructor would change slides by pointing the remote at the screen hanging in the front of the room, like it was a TV, instead of at the projector in the back of the room. I guess the signal bounced off the glass beads on the screen. Anyhow, it's something to investigate. Good luck. Thank you.