Check if what Paul said was the source of your problem (very likely). On the other hand, may I suggest you use my Serial LCD backpack? If all you want is to display a few things on a remote display, hook the serial output from APC220 transceiver to my Serial LCD, save an arduino and you use the arduino with temperature sensor to print things like serial.print("Temp:"); serial.println(temp); every once in a while to the other APC220 transceiver. The serial display understands new line and scrolls the display besides doing a whole bunch of things if you want it to do, say sound an alarm if temp is too high/low. Take a look here:
http://www.inmojo.com/store/liudr-arduino-and-physics-gadgets/item/serial-lcd-back-pack---phi-panel/