I would try changing SetText to the Keys action on a login screen to trigger any event handlers.
See the remarks in this article
http://support.smartbear.com/viewarticle/30039/If your tested application uses event handlers to detect and handle text changes or keyboard input in a control, keep in mind that the SetText action raises only text change events and does not raise keystroke events. If the expected events do not occur when you use the SetText action to change a control’s text, use the Keys action instead.
