Problem with Persistence for DataNormalization

Is DataNormalization supposed to be able to be persisted out of the box or do I have to alter it?

I tried:

	
		DataNormalization norm = new DataNormalization();
                //Configure DataNormalization object here...
		EncogPersistedCollection encog = new EncogPersistedCollection(Config.FILENAME);
		encog.create();
		encog.add(Config.NORMALIZER_NAME, norm);
       

I checked the .eg file manually and the information for the data normalization object was all in there. Later I attempted to retrieve it with:

	
		File file = new File(Config.FILENAME);
		if (!file.exists()) {
			System.out.println("Can't read file: " + file.getAbsolutePath());
			return null;
		}
		EncogPersistedCollection encog = new EncogPersistedCollection(file);
		
		DataNormalization oldNorm =(DataNormalization)encog.find(Config.NORMALIZER_NAME);
		if (oldNorm == null) {
			System.out.println("Can't find network resource: "
					+ Config.NORMALIZER_NAME);
			return null;
		}
       

but I got an exception in the .find method:

Exception in thread "main" java.lang.NullPointerException
	at org.encog.persist.persistors.generic.XML2Object.loadCollection(XML2Object.java:185)
	at org.encog.persist.persistors.generic.XML2Object.loadActualObject(XML2Object.java:145)
	at org.encog.persist.persistors.generic.XML2Object.load(XML2Object.java:87)
	at org.encog.persist.persistors.generic.GenericPersistor.load(GenericPersistor.java:76)
	at org.encog.persist.PersistReader.readObject(PersistReader.java:363)
	at org.encog.persist.EncogPersistedCollection.find(EncogPersistedCollection.java:389)