Android : android failed to start service on boot

my App has a camera photo backup service. When user turned on the service, it will automatically backup sd-card photos to remote server. But when user shut down android OS and boot again, the backup service failed to start again.

I read many articles online, I did exactly the same as they described, but turned out to be wrong. Maybe some experts here can help me. see the code below.

In android manifest.xml

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

<application
    android:allowBackup="true"
    android:name="com.seafile.seadroid2.SeadroidApplication"
    android:label="@string/app_name"
    android:icon="@drawable/ic_launcher">

    <receiver android:name=".OSBootReceiver" >
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <category android:name="android.intent.category.LAUNCHER" />  
        </intent-filter>
    </receiver>

OSBootReceiver class

 public class OSBootReceiver extends BroadcastReceiver {
    private static final String DEBUG_TAG = "OSBootReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.d(DEBUG_TAG, "boot to notic receiver");

        Intent cameraUploadIntent = new Intent(context,
                CameraUploadService.class);
        SharedPreferences settings = PreferenceManager
                .getDefaultSharedPreferences(context);
        boolean isUploadStart = settings.getBoolean(
                BrowserActivity.CAMERA_UPLOAD_SWITCH_KEY, false);
        if (!isUploadStart) {
            return;
        }
        Log.d(DEBUG_TAG, "boot to start service");
        context.startService(cameraUploadIntent);
    }

}

I tried to reboot os many times, but didnt fond any log printed! any advice will be appreciated.