Problem unmarshalling parcelables

I've got a few classes that implement Parcelable and some of these classes contain each other as properties. I'm marshalling the classes into a Parcel to pass them between activities. Marshalling them TO the Parcel works fine, but when I try to unmarshall them I get the following error:

Unmarshalling returned null object from a successfully marshalled XML

i have the following classes which is marshalled as an XML