Bug 30170 [Preferences] editors preferences not stored on OK?
20030121 my eclipse hard-crashed and it seems that the 'number of open editors' preference was lost preference pages should store their values on OK. i guess the 'Editors' page forgot to do it.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceStore.java
defaultProperties = new Properties();
	properties = new Properties(defaultProperties);
}
/**
 * Creates an empty preference store that loads from and saves to the
 * a file.
 * <p>
 * Use the methods <code>load()</code> and <code>save()</code> to load and store this
 * preference store.
 * </p>
 *
 * @param filename the file name
 * @see #load()
 * @see #save()
 */
public PreferenceStore(String filename) {
	this();
	Assert.isNotNull(filename);
	this.filename = filename;
}
/* (non-Javadoc)
 * Method declared on IPreferenceStore.
 */
public void addPropertyChangeListener(IPropertyChangeListener listener) {
	listeners.add(listener);
}
/* (non-Javadoc)
 * Method declared on IPreferenceStore.
 */
public boolean contains(String name) {