Just fyi, just because the post is in the dead post section it doesn't mean it is fully dead. If it is still in the window of time for the original poster to re-upload it then your post can go unapproved since they have priority.
Second, it takes a while for posts to be approved, like a week or so sometimes. Go to the Add Post section, look at the right side. Those are the posts waiting for approval and if you refresh you might see different ones as the limit seems to be about 10 being shown at once, so your post might still be there waiting.
You can try and repost a recently 'dead' post but I find looking for posts that have been dead for at least 2 weeks to be a better chance. This is just my experience so far.