Silverlight EventAggregator not causing bindings to change

Question

I am using the EventAggregator from the Microsoft.Practices.Composite.Events section to all several user controls on the silverlight page to update when it's parent updates. The subscribed events fire correctly and update the properties of my view model, but the view never changes itself.

On my child control view model

EventBroker.Current.GetEvent<UpdateCampaignEvent>().Subscribe(CampaignUpdated);

On the publisher

EventBroker.Current.GetEvent<UpdateCampaignEvent>().Publish(this);

The properties that get updated all call PropertyChanged, and if I call the update manually from the parent view model the bindings update themselves correctly. I was thinking there may be an issue with what thread the events are call on and which one the ui runs on. I have also tried the following:

EventBroker.Current.GetEvent<UpdateCampaignEvent>().Subscribe(
                CampaignChanged, 
                Microsoft.Practices.Composite.Presentation.Events.ThreadOption.UIThread,
                true);