having css break down, cant seem to adjust it right

Hi, on:
https://ocixx.com/nb/

I am trying to fix up the display of the thumbnails, you see there, the single thumbnail below by itself is not inline with the thumb above it, and the left of the first thumb/post has been cut a little bit, i look at this through firebug to try and figure out whats wrong but when i think i found it i cant seem to fix it.. can someone help me clean this up a bit? i cant even figure out how to remove the border around the pictures..
Thank you