WordPress Category Margins Overflowing

I recently made some change that I’m unaware of that seems to be shifting the sidebar of my categories quite significantly.

http://www.invisiblejungle.com/?cat=3

I’ve looked through the CSS and PHP, and I’m not entirely sure what’s causing it… I presume that whatever fills the sidebar is what’s causing it to flood in this manner, but after a month, I’m unable to determine the issue.

Does anyone have any ideas?