<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <PreferenceCategory android:title="Notifications">
    <CheckBoxPreference 
            android:key="vibration"
            android:title="Vibrate" 
            android:summary="Vibrate phone for notifications" />
    <CheckBoxPreference 
            android:key="play_tone"
            android:title="Play Ringtone" 
            android:summary="Play Ringtone for notifications" />
    <RingtonePreference
            android:key="app_ringtone"
            android:dependency="play_tone"
            android:title="Select Ringtone"
            android:ringtoneType="notification"
            android:showDefault="true"
            android:shouldDisableView="true"
            android:summary="Pick a Ringtone" />
    </PreferenceCategory>
</PreferenceScreen>
This is my preference xml. But,
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
prefs.getString("app_ringtone", null);
always returns null. I am debugging on a device (HTC Wildfire).