I was trying to figure out why the titles of my RadPanes were not being translated. I finally figured out that the LoadLayout() also loads the header of the panes and that overrides my XAML's {x:Static properties:Resources.xxx}.
I could say "After the LoadLayout(), change the title of each pane according to the resource strings" but it would be nice if it could be done directly in the XAML. I don't believe there's a way to prevent the "Header" tag from being included in the SaveLayout/LoadLayout functions, right? To tell you the truth, I don't even see why the header is included at all!