Cross-browser problem: Image displacement

I’m having a problem at http://www.jonnyjimison.com/
See the green box with the social network icons in it? On Safari, Chrome, and most other browsers I’ve tried, it looks perfect: the icons centered in the green box. But Internet Explorer 8 shuffles them slightly down and to the left. Earlier editions of IE place the icons correctly, but off-set the “credits” and “purpose” icons on the bottom of the sidebar.
I’ve wrestled with the social icons for days, but I’m at a loss as to what’s causing this or how to fix it. Any ideas?
I think with some work I can figure out the problem with the “credits” and “purpose” links, but if you know what’s going on there, I’d appreciate any advice about that problem as well.
Thanks!