In pages like http://en.wikipedia.org/w/index.php?title=User_talk:Redrose64&diff=curr , no editsection links are shown, even though the page displayed is (by definition) the current version. Curiously, there are editsection links on http://en.wikipedia.org/w/index.php?title=User%20talk:Ucucha&diff=curr .
These links used to appear until earlier today. The bug is presumably caused by r108622, which merged r100756 and r92703 into 1.18wmf1. Not sure which of those is the culprit.