Bug 41927 [Dialogs] Selecting in PreferenceDialog generates too many invalid entries
20030825 If you select an entry, close the dialog and then reopen it selecting anotehr entry will result in a "this page has invalid values" although you selected nothing.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
preferenceManager = manager;
	}
	/* (non-Javadoc)
	 * Method declared on Dialog.
	 */
	protected void buttonPressed(int buttonId) {
		switch (buttonId) {
			case IDialogConstants.OK_ID :
				{
					okPressed();
					return;
				}
			case IDialogConstants.CANCEL_ID :
				{
					cancelPressed();
					return;
				}
			case IDialogConstants.HELP_ID :
				{
					helpPressed();
					return;
				}
		}
	}
	/* (non-Javadoc)
	 * Method declared on Dialog.
	 */
	protected void cancelPressed() {
		
		Iterator nodes =