A similar situation exists with string controls. To provide a way around that, you can tell LV to update the string value with each keystroke. Unfortunately, a similar option doesn't exist for numerics.
BTW: the same issue exists if you are trying to capture value change events on numerics. As a more general work around, I created a VI that uses a control reference to force the button I press to have keyfocus (and thus remove it from all the other controls) before the software responds to the press itself.
Mike...
