title: Why does preferences.getString("key", "DEFAULT") always return "DEFAULT"?
body: <p>I have user_preferences.xml in my XML directory. A PreferencesActivity uses this file to create the user preferences activity.. and that works. Whatever the user selects here persists. But I am unable to retrieve the value the user selected. </p>
  
  <p>When I use... </p>
  
  <pre><code>SharedPreferences preferences = getSharedPreferences("user_preferences.xml", 0);    
  String mapTypeString = preferences.getString("map_type_pref_key", "DEFAULT");
  </code></pre>
  
  <p>... mapTypeString is always "DEFAULT". </p>
  
  <p>It seems like my user_preferences.xml is not found when I instantiate my SharedPreferences object. But, the PreferencesActivity finds it, of course. So, what am I missing?</p>
  
  <p>Many thanks!</p>