Would it be possible to throw a different exception if you're trying to call AddXXXResult and the property isn't in the list of AffectedProperties? Something that would be clear without opening the Csla source would be great. 
I'm sure Csla could add a better exception message to the ArgumentOutOfRange exception.
http://www.lhotka.net/cslabugs/edit_bug.aspx?id=982
Awesome, thanks for adding that!
Copyright (c) Marimer LLC