User blog comment:Kirkburn/Technical Update: September 23, 2014/@comment-4129195-20140923175253/@comment-1038387-20140923180823

Check whether the date of the last cache has been updating. It sometimes skips a day or two. Or, if it's a link in a template, it doesn't clear the old links from the pages on which the template is used. A null edit on those pages solves that.