differences Firefox/Mac & Firefox IE, footer breaking up

This is my first time noticing differences in Firefox/Mac and Firefox/IE.
On a global footer i’m creating it was breaking up in Firefox IE.

does anyone know what the root cause would be?, so i can remedy correctly?

this footer uses a list, list items are floated and margin-right property is used to spread it out across the bottom of a page. last item has it’s margin-right prop set to 0.

is there a better method to use to achieve this same thing?

here’s the URL:
[url]http://www.tomcarden.net/hm-site-from-server/procedures.php[/url]

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