I think there's a problem to change legend panel orientation when RadChart control starts with that panel visibility collapsed.
I have a project with two RadChart controls with same data. First control starts with legend panel visible, the second starts with panel collapsed.
I have a button for each control to change orientation. For the first chart, changing orientation works fine, for the other doesn't.
I'm using RadControls for Silverlight v2010.1.422.
ChartData is a separate class file with two automatic properties: Name and Value