I was assuming that setting CheckCurrentRowBeforeNavigate to True would cause a rule check when I moved between rows in a grid however my rule only fired when I tried to save a change. I've tried this with a DevExpress and a standard Data Grid and the behaviour is the same.

Is there something else I need to do to check business rules before the user presses Save?

Cheers, Peter

This is not respected when going through the BusinessBindingSource in most cases.  This has to do with the nature of a grid and how the interaction to stop navigation would actually take place if there were in fact an error.