Issues with image spacing/padding in certain browsers

I've been trying to integrate the matrix theme into a site. It looks exactly how I want it to in IE, but in Firefox, Chrome, and Opera (the only other 3 i've tested) there is about a 5 pixel space under each of my header images. I've gone through the CSS (with Firebug) and tried every which way to get rid of the spacing/padding/margin/whatever it is and can't do it (even removed all CSS and it still does it). If I put my layout in a fresh html page with none of the gallery code in it, it displays correctly in all browsers, but when I cut it up and put it in the tpl it has this weird 5 pixel spacing under the header images (except in IE). I've also tried laying it out with tables instead of <div>'s but get the same thing. I know there are probably other/better ways of designing the layout than the way I have it here, but i'd really like to figure out the cause of this for future reference at the very least. If anyone can help, I would greatly appreciate it.

Here's the link:
http://www.dt52photos.com/gallery2/main.php