Hi BL2, I just wondered how your pro box worked after adding the extra IR receiver. Mr Bachmann said to just cut off the square tab, but didn't say if it mattered which way the plug went into the IR receiver. The IR cord has 8 pins (same as an 8 pin decoder) and you have a 50% chance of getting it wrong! I have a pro box and was going to hook up the 2nd IR receiver and saw your posting on this forum. The IR extension has the notch-out to put the cable in one way only, the IR receiver should have a notch-out as well