Actually ... I have it working now. While I was testing with the IR pair as one of my input signals, I also had several buttons connected as other input signals. It seems one of the buttons is faulty and sending continuous high value and leading me to a wrong conclusion. So, I have 4 buttons and one IR pair (as a testing scenario) and inputs give accurate high/low states. This is terrific, although I am surprised that IR is working this way; I would have expected the constant power from the IR pair to throw off the high/low state for that input pin.