I just took a look at the page. I see the social stream on the left. The bottom-most post doesn't have the rounded border at bottom automatically. However, that area is scrollable and you can move through all the posts available by scrolling. The bottom post, after scrolling, is closed. That's how it's supposed to work by design to show as many posts as possible in whatever area you've specified.
I hope that helps explain, but if that's not the issue you were having, let us know.
Thanks,
Alex