Oddity in firefox where hidden elements till take up space
If you'll take a look here: http://dmsuperman.homeip.net/portfolio2/ in both IE and Firefox, you'll see some differences.
Firstly, open it up in IE. Look at the arrow buttons for the images. The numbers are all as they should be (25 x 25) but for some reason, the images inside the links for the arrows cause a random extra 4 pixel border to appear below the image but inside the link. If I change the arrow image to some other element (ie a span tag or just plain text) then it works just fine, but for some reason the images inside the link cause the link to have an extra 4 pixels of bottom padding. I tried adding a border to the image to test it out, and the 4 pixels are not inside the image element, they are below it, so it's either 4 pixels of margin on the image or 4 of padding on the link.