How do I tell if the browser window is Maximized in Silverlight/C#?

Question

How do I tell if the browser window is Maximized in Silverlight/C#?
The "Form" maximize feature will not work because I am writing a silverlight app that runs in the browser.
I have tried this:
App.Current.Host.Content.FullScreenChanged += new EventHandler(Content_FullScreenChanged);
but this event handler is not called when I maximize the window.
Maximized is not full screen
App.Current.Host.Content.IsFullScreen;
returns false even if I maximize the window.