Well- that's weird that some rules like this work and this one doesn't. Is the default in all of them set to change if the data source is updated? I don't like default values - I prefer to use rules all the time, because I'm a control freak. You could test removing the default value (just temporarily) to verify the issue is not with your rule that sets it to N/A, that may be worth a try.
Hilary Stoupa
