I'm sure this is a simple error, but I can't figure out what I'm doing wrong

My problem is that I can pick up the background color for my page if I put the code directly into each page, as follows:
=====================================================
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<!-- Created with the CoffeeCup HTML Editor 2008 -->
<!-- http://www.coffeecup.com/ -->
<!-- Brewed on 13/08/2009 16:10:31 -->
<head>
<style>
body{background-color:#FFFFD8;}
</style>
<meta http-equiv="content-type" content="text/html;charset=utf-8"/>
<meta name="generator" content="CoffeeCup HTML Editor 2008 - www.coffeecup.com"/>
<link rel="stylesheet" type="text/css" href="css/NFC_main.css"/>
=================================================
However, this defeats the purpose of the css. If I take the style tag info out, and put the style into the css (NFC_main.css) as folows, the color is not picked up:
==================================================
<!-- Style Sheet created with the CoffeeCup StyleSheet Maker -->
<!-- http://www.coffeecup.com -->
<style type="text/css">
<!--Body
{background-color:#FFFFD8;}
div.wrapper {
margin-left : 10%;
margin-right : 10%;
}
H1 {
font-family: Papyrus,Palatino Linotype,Georgia,serif;
font-size: 22px;
font-weight: 700;
font-style: normal;
text-decoration: none;
text-transform: none;
font-variant: normal;
color: #80A82B;
text-align: center;
}
=================================================
Everything else I can control centrally from the css. Can anyone explain what I'm doing wrong with the background color tag in the css? I have searched the internet and this site and this seems to be the correct syntax.
My site is http://www.nikkifieldconsulting.com
I'm using HTML Editor version 12 build 412 (registered) on Windows 7
Thanks for any help.