The page I have developed for my freelance business has been giving me some trouble. In the process of testing I have noticed that my center menu is one pixel higher on Macs than it has been on the PCs I have tested. This is consistent across many different browsers (IE, Firefox, Opera, Netscape).

The first part of my question is why is this happening.

The second is how do I fix this, or avoid it in the future.

I have changed the css so that it looks correct on PCs, but would like Mac users to see it properly as well.

The site can be seen at http://www.populistdesigns.com