When I change state the UI does not update

Question

I have some code that uses state changes to manage the buttons in a login screen:
        <mx:states>
                <!-- Default state: the LoginWindow accepts input from the user -->
                <!--  Login
                        login is in progress.
                        No input allowed other than the "Cancel" button
                -->
                <mx:State name="{STATE_LOGIN}">
                        <mx:SetProperty target="{loginForm}" name="enabled" value="false"/>
                        <mx:SetProperty target="{loginButton}" name="enabled" value="false"/>
                        <mx:SetProperty target="{cancelLoginButton}" name="enabled" value="true"/>
                        <mx:SetProperty target="{statusLabel}" name="text"
                                                        value="{resourceManager.getString(ResourceNames.BUNDLE_NAME,
                                                        ResourceNames.LOGIN_CONNECTING_STATE)}"/>
                </mx:State>
The problem is that when I change the state by setting currentState to STATE_LOGIN the UI change does not happen right away. In fact it doesn't take place until the login event is complete, creating a race condition.
However, I've been able to work around this problem by explicitly setting the values of loginButton.enabled and cancelLoginButton.enabled in my program:
          loginButton.enabled = false;
          cancelLoginButton.enabled = true;
When I do this, the buttons are enabled in the right way.
Why does explicitly setting the button enabled flags work, but the state change, which should do the same thing, not?

Answer 1

Nope, that's not it. I just now tried changing the state values to constant values and it did the same thing. Also, BTW, the state eventually does change even with the binding expressions -- it just doesn't change until after the login is done (I also tried putting the call to the login in a callLater; made no difference). But, as I said, when I assign to the enabled fields the change happens right away.