Android proximity sensor giving false results - android-sensors

Question

First post here, but stackoverflow has solved soooo many problems for me. This one though, I can't seem to figure out. I'm creating an android app that de-increments and TextView value by 1 with every proximity detection. For some reason, when the Activity starts or resumes (power button), it logs 2 proximity hits. I've double-checked to ensure that I'm not close enough to the detector when pushing the power button.
Here is the code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.exercise);
//start proximity
startProximitySensor(sensorListener());
}
private SensorEventListener sensorListener(){
listener = new SensorEventListener(){
#Override
public void onAccuracyChanged(Sensor arg0, int arg1) {
// TODO Auto-generated method stub
}
#Override
public void onSensorChanged(SensorEvent event) {
if(event.sensor.getType() == Sensor.TYPE_PROXIMITY){
String maxRange = String.valueOf(mProximitySensor.getMaximumRange());
if(event.values[0] == Float.parseFloat(maxRange)){
updateTextView();
Log.i(TAG,"Proximity Sensor Reading: "+ String.valueOf(event.values[0]));
}
}
}
};
return listener;
}
private void startProximitySensor(SensorEventListener proximitySensorEventListener){
mSensorManager = (SensorManager)getSystemService(getApplicationContext().SENSOR_SERVICE);
mProximitySensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
if(mProximitySensor == null){
Log.i(TAG,"No proximity sensor found!");
}else{
proximityStarted = true;
Log.i(TAG,"Proximity started");
mSensorManager.registerListener(proximitySensorEventListener,mProximitySensor,SensorManager.SENSOR_DELAY_UI);
}
}
I've managed to get around it by creating a timeStamp in onResume, and comparing that to the SystemTime generated on each sensor change. If they differ for anything less than 1 second, then the TextView won't update. This works, but I'd still like to know if I'm missing something.
Thanks in advance