Android XML Preference issue. Can't make it persistent

[Denisax]

I have a very simple activity just to show the preference fragment:\[code\]public class PreferencesActivity extends Activity {Fragment frag = null;@Overridepublic void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); FragmentTransaction ft = getFragmentManager().beginTransaction(); if (frag == null) { // If not, instantiate and add it to the activity frag = new PrefsFragment(); ft.add(android.R.id.content, frag, frag.getClass().getName()); } else { // If it exists, simply attach it in order to show it ft.attach(frag); } ft.commit();}private static class PrefsFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); }}}\[/code\]and preferences.xml with persistent to true:\[code\]<?xml version="1.0" encoding="utf-8"?><PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" android:enabled="true" androidersistent="true" android:title="@string/settings" > <EditTextPreference android:dialogTitle="@string/dialog_ip" android:negativeButtonText="@android:string/cancel" androidersistent="true" androidositiveButtonText="@android:string/ok" android:title="@string/ip" /></PreferenceScreen>\[/code\]if I open the EditTextPreference, write something, close the dialog and open it again. The value is still there. But that's it... if I click the Back button, and enter the again on the preferences screen, I already lost what was written. If you exit the application also doesn't save.Am I missing something here?Running on:Android 4.0.3Asus TF300