Ghost unread Items

I get this sometimes in the list it shows unread items (number) but nothing is shown as being unread, it occurs on various items occasionally, I normally clear it by, Mark Unread

Win 7-x64 Chrome 28.0.1500.52 m


I had this too (Free account for now) and I went to disable a site under that category (as part of my 64 allowed) and then re-add one, and it let me clear the ghost unread item