It's driving me mad, every single article I open from the "Unread Content" screen seems to add one random article from the last few months to the list, most from between the 11th and 15th of August. I see four articles from the 11th of August, read one, back to Unread Content - 3 left. Good. Open another one, back to Unread Content - three left again, but not the one I just opened. Aaarrgh! It doesn't matter which browser or OS (Windows/Mac) I use.