Custom XML binding causes word doc to lose content control style/font

I am trying to do a word document that has content control bindings to an XML document that I am swapping out for custom.xml in the word docx package.

When I created my original docum开发者_开发问答ent, I added fonts and size and style to the content control text. This made it fit the rest of my documents style.

Then when I swap in the custom XML content, and re-open the document, all of the style stuff is gone and it is showing up as a Calibri font size 10 - nothing like the arial size 18 bold I specified.

What is going on here?

Is this Word 2010 or 2007. I seem to recall XML content controls being removed as a result of a lawsuit with Microsoft, so that might not be a good strategy moving forward.