I suggest that a <br> is added before the signature is displayed, because is a "one-line-post" is posted, it's kinda hard to read (at least that's what I think).
Look at the posts of MarkJH and myself (this topic), the post itself and the sig are stuck together, while the "back to top" image adds space to the next post.
Well, I'll surely edit that in my future v3.4 forums.