Multiple page post overlap weirdness

I've noticed something weird. There seems to be 20 posts per page (at least in the first because I don't know how this affects the later pages.)
Anyway, the posts in the later end of a page seems to overlap to the next page. So using an example of an RP thread I'm in. There are 23 posts (including starting post) so since there are 20 posts per page, there should be 3 posts on page two.
Not so. The nine last posts from page 1 also appear on page two making page two 12 posts long when it should be three posts long.
Anyone else experiencing this? Anyone know what's going on? Bug or Feature?

Don't worry, it isn't just happening with you, that's how this forum is set up.
I'm not sure if the admins set it to this, or if it comes with forum-motion forums, but yeah.

Comparatively, this is somewhat of a new feature. ((I went away for a while, came back, there it was.)) My guess is that it has to do with posts at the end of a page. If someone makes a post and it's the last one on the page, then another person makes a post that starts a new page, there's always the chance the first person's post may not be read as others would jump to the most recent page when reading what they have missed.

Just my guess though. Admin-Sama should be able to tell us more.

actualy I had been wondering who did that, i think its a handy feature and all but I have no idea how it happaned....

I think it was an update to all forum motion forums, personally I find it handy, the forum I made is the same now