An empty space I can't get rid of with CSS

Maybe I’ve written too much code and can’t find what’s wrong, but

http://mtsix.com/articles/2006/02/the-perfect-site-structure.html#comment-3210

If you have Firefox and the Web Developer extension, outline the elements: dt, dd, p, and dl.

You’ll see that in between the commenter’s name and the comment, there is a gap of about 10px. I just can’t find what is making that and can’t get rid of it.

Is there a firefox extension that looks at the rendered css property of each element or something? It’s so frustrating when doing something like this.

Any help is appreciated.