Rollback data didn't not work on list attribute

##Here is Model definition.

I use CouchDB as my database.

Erp.ListTransform = DS.Transform.extend({
    deserialize: function(serialized) {
        return serialized;
    serialize: function(deserialized) {
        return Ember.A(deserialized);

Erp.Product = DS.Model.extend({
    brand: DS.attr('string'),
    category: DS.attr('string'),
    spec: DS.attr('string'),
    desc: DS.attr('string'),
    cover: DS.attr('string'),
    rows: DS.attr('list')

When I change the rows value. the model’s isDirty property is still false. So rollback won’t work on list.

I use reload to rollback data. It works, not the other attributes like brand or category, are not rollbacked. And reload function request the server.

Is there any solution? OR my transform should be changed?