I think (I could be wrong) that because you posted it that it's not "new" to you. I've been having issues w/replies to threads I'm subscribed to not showing up in my notifications. Biggest issue is when it's a "parts for sale" thread that I started.
after you post something, the application sees you already read it. It would not be included in New Posts. Now that I have replied, you should see it in New Posts. Troy
Until you read it, then it disappears. Upper right side is a link to "recent posts". Then you can see all. Devon