I recently had a very annoying error - it appears that I got an OptimisticLockException on an object that hadn't changed.

Could not synchronize database state with session org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [books.db.Business#64491]

books.db.Business#64491 is an entity related to the operation being performed but none of its fields are being changed, only fields that it is related to

Have I misunderstood the rules for the OptimisticLockException - that it would fire only if a field on THAT object had changed?

Do lock operations cascade?

Any ideas on why this might be happening?