My keyless entry remote has stopped working suddenly. I have tried fresh batteries and the remote "chirps" when I press either button. This is a Volvo replacement unit to replace a lost one and is only 4 months old. It has not been dropped, stepped on, wet or even looked at funny to make it stop working. I also attempted to reprogram following the instructions in the owners manual also with no sucess. To add to the confusion the remote that my wife carries still works fine. I even tried swaping the batteries and mine still doesn't work and hers still does. I would appreciate any help on possible casues and repairs for this problem.