I feel stupid for having done this, but I am sure somebody else must have done it too.
You hit post reply at the top of the thread to create a reply to a thread...makes sense, but after you've typed your reply the "post reply" button is still there looking like the thing you should hit instead of the "submit" button hiding below the text entry field; I think this is a usability issue that may confuse some users. Sure, it's obvious what you are actually supposed to do after you hit it, but by then it's too late and you feel silly as you re-type your reply.
Tell me somebody else did this too.
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