>>Exactly. So is it a bug or am I using Assign improperly?
>
>Improperly. Think of changing the value of a control via its user interface as changing the state of the control and its controlsource itself, not setting variables, per se. We've got ProgrammaticChange and InteractiveChange for traping changes in the controls state while Access and Assign are for trapping changes in the property's state. Make sense?

IMHO, I don't think it is improper use. We had only ProgrammaticChange and InteractiveChange for trapping changes in the controls state before. _Access and _Assign were added later. Since we got them, we may use them with any properties we want, as VFP documentation clearly states that:

"Access and Assign methods can also be created for all native Visual FoxPro properties. " (Chapter 33: Programming Improvements)

If some of them don't fire we can consider it as a quirk or a bug.