1) This isn't 1997, which is the last time anyone had any real business using the LONG deprecated CENTER tag.
2) Looking at your site, you've failed to grasp a lot of the concepts of HTML -- like you can only have ONE body tag, not three... that in a STRICT document (which your doctype is setting) you aren't supposed to use CENTER, FONT, or any of the half dozen other tags you seem to be using. I would suspect that you are learning from a decade or more out of date source... Multiple H1's around non-heading elements, markup AFTER the HTML tag is closed -- you've basically got gibberish here... and the use of so much presentational markup makes one question why you even HAVE CSS.
Not even sure where I'd start to think about fixing that. Pretty much ALL of the markup needs to go.