I have been looking through some reports on Google Analytics and if I go to CONTENT > Site Content > Pages
and filter by Page Title
my highest visits Page Title is (not set).
If I drill down into this to find the pages responsible they are all pages with titles (and indeed pretty much all of them are returned by the Page Title view with their titles).
I started playing about with the site trying to view it in various ways with different things enabled and disabled in order to see if I could ever make the title not appear on the pages listed, I just couldn't.
Has anyone come across this before and could provide me with a set of next steps in order to see what is happening.
I have checked the advice given in this question and can report that the tracking code as not been altered in any way that would have logic to create this.