I turned it on just for the blog on a site I'm working on and it's doing the inverse of what it should. All the internal links (like "Continue Reading ->" links) are marked with the icon, but external links are not.
When I set it to "All Content" as a test, all my menu links had the icons. Very Odd.
Any idea what could be causing this inverse behavior?
I should note I used it on another site recently without a problem, so I'm baffled.