Space between posts

I’m really stumped here. The main page of my site has the correct spacing between posts, but on any archive page, they overlap. I’ve looked at the php code for the archive class vs the index page class, and all the code inside the while loop that displays the posts is the same. I don’t understand how they could display differently is that’s the case?

This page is correct: carissalyn.com
this one isn’t: http://carissalyn.com/category/brockton/

Here’s the code inside the while loop in the archives class:

[code moderated per forum rules - please use the http://pastebin.com/ ]

I can post the corresponding css too, but I don't see how it could be a css issue when both classes are using the same code, and thus the same css.