Dunno if it is a bug but I am having the same problem i think. I have already logged a JIRA issue and I believe someone is looking into it.
Has anyone else got problems? I would have thought this would be an easy bug to spot (because the feature is so darn useful). Part of me thinks im doing something wrong. I cant see how though.
see also (related issues) :
This case (reported by my collegue) is fixed by removing the cascade annotation on the non-owner side.