Core Data Set Relationship from Inverse

Core Data Set Relationship from Inverse

I have a bunch of code that sets Core Data relationships via the inverse
instead of the "addWhateverObject" methods. This usually works well in all
of my applications, but I have one app where the relationships are being
lost when the NSManagedObject context is being saved.
My question is setting a relationship in Core Data via the relationship's
inverse valid or do you have to use the accessor methods to add objects to
the relationship?
Thanks!