I’ve noticed a number of times now where Google are adding Comments on: to Page titles even though the phrase Comments on: is not in the page title and nowhere in the source code.
I assume it is something to do with WordPress comment system but at the moment have no idea why Google are including it in page titles in the results pages.
You can see some examples here;
site:http://www.v1seo.co.uk/ “comments on:”
site:http://www.sim64.co.uk/ “comments on:”
It is even happening to Matt Cutts
site:http://www.mattcutts.com/ “comments on:”
(go to page 4 to start seeing it happen)
Screenshot after doing search for site:http://www.v1seo.co.uk/ “comments on:”