Welcome to Skylines Australia
You will find that when you transfer the post to the top of page, the marker for new posts is reset to the bottom of the page. When the markers reach half way up the page the new post is then added to the bottom. If the amount of letters you have typed exceeds 100, then the the post is automatically moved to the latest section, usually corresponding to the time of day, but only on weekends. During the week - your post is automatically updated in whatever location your post is finished from..
That should make it a bit clearer!