Using WCF RIA Services and entity framework 4.
I have 3 DTOs: School, State, District. The state DTO has a District property with composition. And the School DTO has a State property with composition and a District association.
The idea, is that when we create/update a school, we also allow the user to enter the state and district (which can be existing or new).
When creating a new state and district, everything works fine. But when I create just a new district inside of an existing state, I get the following error: "This entity is currently read-only. One of the following conditions exist: a custom method has been invoked, a submit operation is in progress, or edit operations are not supported for the entity Type"