Disable right click "Silverlight" popup in comboboxes

Question

Hi I'm trying to get rid of the annoying "About Silverlight" context menu that pops up whenever you right click in a Silverlight application. I've added the usual ways:

In App.xaml
rootVisual.MouseRightButtonDown += ((s, args) => args.Handled = true);

and the same for all ChildWindows. The problem that persist is in all "pop up"-controls like comboboxes and datepicker calender popup. There I can't get rid of it. I would like to handle the right click in a style that I can make implicit for the entire application. Is this possible? Can I solve it some other smart way?

Best
Daniel