All of a sudden today, my IR543 no longer accepts commands from my T2 in a reliable manner, neither via direct IR nor via the IRF-6 with emitter.

I tried changing repetitions (0-2) and frequencies (between 38.5 and 41 kHz, what is the correct frequency anyway?) for my X-10 commands, but no difference.

My IR543 works fine with the IBM Home Director remote (RS 15-1924). But when I use the buttons on the IR543 directly, it often gets confused (sending a command to multiple addresses etc.)

What the freak is going on?