Well, at first, it seems that only the ribbon control is in RightToLeft mode, but not the form, as its buttons are not moved.
I would suggest using RadRibbonForm (http://www.telerik.com/help/winforms/forms-and-dialogs-ribbonform-overview.html), which will take over the task bar as well. You can modify this behavior with the AllowAero property of the ribbon form.