Removing spaces between tiled photos

Hello! I’d love any help available with removing the spaces between images on this page

http://www.invsoc.org.nz/we-are-invsoc/

When I edit in Compose mode, theres no spaces, the images tile against each other. I’ve made the small thumbnail images the right size so they all stack together pixel perfect….except on the actual viewed page, theres always white space between them? White lines?

Do you know why this is happening, could you help? I dont see anything in the code that should be making this invisible horizontal space?

Any help you could offer would be hugely appreciated! I’d just like all the images to touch each other, as seen in the Visual editor mode

http://www.flickr.com/photos/jaywontdart/7115530701/sizes/l/in/photostream/

Here is the full code from the page, thank you very much for your time!

[Code moderated as per the Forum Rules. The maximum number of lines of code that you can post in these forums is ten lines. Please use the pastebin]