I changed the batteries, now when I use it, I simply get "P1, P2, P3, P4" auto cycling through the monitor, I can speed up the cycle if I hit 'mode'.. So the monitor is pretty much useless now, I did check the reed switch and magnet and it made no difference, I tried holding the buttons in various combinations for various amounts of time, I just can't get it to work.. Can anyone help?