Currently, if a node positioned using right is inside an rtl block, Y.DOM.setXY fails to position it correctly.
You can check this behaviour in this fiddle. You can see how the last node never gets positioned correctly.
As per the specs, inside rtl blocks, right trumps left, so if a node is already styled using it, the inline position will never apply.
Y.DOM.setXY should switch to a right-based calculation in this case.