Posting on one of the trending posts (possibly even the latest ones) either duplicates the post in the next thread that takes that spot OR actually only posts in that spot, this bug has been around for quite long enough I'm sure it's been noticed by others, after all one does not simply mistake "I'm 13 and want $40, what should I do?" with "How are we supposed to get strange coins now that the weekly heroic is gone". examples of this bug are pretty easy to find, go to a trending post and scroll until you see comments that are obviously in the wrong thread.