I'm glad I saw this thread....I was just getting ready to complain about my 2 month old IR543. I am having the same problem - as soon as I touch one of the buttons on the 543, the red light locks on and I lose all control until I unplug the unit. After plugging it back in, I might get one more use out of it, then it locks up again. I only have 1 x-10 module so far in the whole house, and it is only 3 feet away from the IR543. HELP