XML : Word 2013 CustomUI Schema Update Issue

Not sure if this problem is unique to my system or not. Background is I have a Word template that contains a custom tab on the ribbon, and I've been asked to make updates to the backstage as well. This template has some simple macros, and I modified the ribbon using this method. Currently using 2013 though I originally started using this method in 2010.

Seems like ribbon and backstage are sisters, but seems I'm having issues with the schema.

The markup I've been using starts with this:

  <customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui">    

But if I try to add backstage elements, not only do those not show up but my custom ribbon disappears as well. I read from here that the backstage elements were in an update to the schema and that I should use this:

  <customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui">    

However neither backstage or even an extremely simple ribbon markup works under this schema, tested together and separately.

As I'm typing this I'm beginning to suspect my rels file, which currently has something quite similar to this:

  <Relationship Id="someID" Type="http://schemas.microsoft.com/office/2006/relationships/ui/extensibility" Target="customUI/customUI.xml" />    

With the 2009 schema, do I have to update the relationship type in my .rels file? What would it be? Is it as simple as replacing 2006 with 2009?

Or does it have nothing to do with the relationship type, and there's something else at play here?

Any input helps! Do I somehow need two customUI files for the backstage and the ribbon? Am I missing a step?