To Matt:

Here is an example of how you can fix your issues. You need to first move the Notification Handling functionality into its own class and instantiate it in App.xaml.cs.

Also, in your App.xaml.cs, add code to unsubscribe from Toast Notification in Application_Launching and Application_Activated.

 Example:

 if (httpChannel.IsShellToastBound) httpChannel.UnbindToShellToast();

 

Then, add code to subscribe to toast notfication in Application_Deactivated and Application_Closing.

 

 Example:

 if (httpChannel.IsShellToastBound) httpChannel.BindToShellToast();

 

This will take care of the XmlException issue

Paul Wu