i think, you try to put google analytic code in header of your page
on which Google+ button is .
it happened with me some this i put google+ button code in my page and its not showing and when putt google analytic code in header its star showing it happened with me 3 times.
you should try this put google analytic code and check it. but i can’t say it surely but you shoult try it if you don’t have google analytic code in header file.