Ah, OK, it's not "perfectly" centered. I didn't notice at first.
You have put MSIE into quirks mode by adding the xml prolog at the top of the source. <?xml version="1.0" encoding="utf-8"?>
MSIE thus uses the old box model, making the paragraphs narrower. Since you're floating them to the left, there's extra space on the right.
#footer { float: left; display: inline; position: relative; width: 698px; padding: 0 15px 5px 15px; }
In quirks mode, that means the footer is only a total of 698px wide (with the padding subtracted to get inside width).
In standards mode (as with Firefox and Opera), left and right padding is added to that figure, for a total width of 728px.
Regards -- Bert Doorn, Better Web Design http://www.betterwebdesign.com.au/ Fast-loading, user-friendly websites
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