Android :: Why Preferences Page Not Show Current Values?

I have a preferences page which is defined by XML - including some default values. I use a PreferenceActivity to display and handle this page. Whenever I use this page to set the preferences the preference file on the file system is updated properly - I can see this via adb. However, whenever I go back to the settings page after have changed some of the settings, it's the defaults that are shown. Worse than that, if I press back without changing any settings, it then sets the, all back to the default. How I can get the prefs to actually show the current settings? My PreferenceActivityis created thus:

@Override protected void onCreate(Bundle savedInstanceState) {
PreferenceManager.getDefaultSharedPreferences(this) .registerOnSharedPreferenceChangeListener(this);
setDefaults(this); super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.settings); }

The XML looks like this:
<?xml version="1.0" encoding="utf-8"?> <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<ListPreference android:id="@+id/numberOfYearsList"
android:key="numberOfYears" android:title="Number of Years to Read the Bible"
android:summary="How many years would you like to take to read through the reading plan?"
android:entries="@array/numberOfYears" android:entryValues="@array/numberOfYears"
android:dialogTitle="How Many Years?" android:defaultValue="1" />
<CheckBoxPreference android:key="ignoreDates" android:id="@+id/ignoreDatesCheckbox"
android:title="Ignore Dates" android:summary="Would you like to use the dates in the plan?"
android:defaultValue="false" /> </PreferenceScreen>