FYI for the forum. I have a 45A00 wireless receiver, 2 keypads and 2 touchscreens, and had been experiencing the random beeps and all on/all off events, and random thermostat setting changes.
I tried swapping the affected keypad console with a new keypad, changed console addresses, even re-spliced some connections, but the problem was not resolved.
I disconnected the 45A00 wireless receiver and the issue went away. Now on to try an alternative wireless solution...