Since you are running at 3V you may have an input level problem. If the IF PORTA.1 = 1 never goes true, the hardware just may not be seeing the proper level. If the input pin is "TTL" level then it needs a voltage level of (.25 VDD + 0.8V) for a '1'. If it is a schmitt trigger then it needs at least 0.8VDD for a '1'. Sometimes it is the simple stuff you need to check.