If you setup a Rackspace cloud File account...create several root folders "A", "B", "C". Then right click on "A" and create a new folder called "D", "D" then gets created as another root folder. To make "D" a sub-folder of "A", you need to double-click "A" right-click create new folder. This is counter-intuitive and not the behaviour I would expect in an "Explorer" view.