CoreData - ManageObject invalid after save

Have been using coreData for a short while and have not had any issues with the data model at all.

However, I have an managed object that appears to have become invalid after a save and any modification to it after the save causes exceptions.

This entity is a parent in a 1-m relationship. For the first save (selecting child items from a table and saving each time to preserve data between views), all is working as expected.

On the next addition of children to the NSSet (in the parent), it throws the exception. I have tried to reload the entity from a fetch and saving开发者_开发问答 it again,

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Are you doing a retain of that object? Are you removing some reference from the object?

Check this article and try to find a more exactly problem: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/CoreData/Articles/cdTroubleshooting.html