Here's two screen shots, showing the effect with a small viewport that has to be scrolled.

HTML looks like this: (ignoring head and html tags)
<body>
 <div id="grad1"></div>
 <div id="wrapper">
 <header>
  <h1 class="logo"><a href="/">Business Name</a></h1>
 </header> 
 <nav>
  <ul>
   <li><a class="first" id="index" href="/index.php">Home</a></li>
   <li><a  id="whatwedo" href="/whatwedo.php">What we do</a></li>
   <li><a  id="communicating" href="/communicating.php">Communicating</a></li>
   <li><a class="last" id="contact" href="/contact.php">Contact Us</a></li>
  </ul>
 </nav>
 <div style="clear:both;"></div>
 <section>
  <?= $content ?>
 </section>
 <footer>
  © 2010
 </footer>
 </div> 
</body>
And the (trimmed down) CSS relating to body, grad1 and wrapper look like this:
body {
 color: #111;
 background-color: #3E9C9D;
}
#grad1 {
 height: 600px;
 position: absolute;
 top: 0;
 left: 0;
 z-index: -100;
 width: 100%;
    background-image: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#3E9C9D));
    background-image: -moz-linear-gradient(#fff 0%, #3E9C9D 100%);
}
#wrapper {
 max-width:960px;
 min-width:840px;
 margin: 0 auto;
}
How do I fix this? I have to have the gradient on a different div as far as I know, because I need to specify the height.
(I am aware that the CSS gradient doesn't work in IE - there is a background-image there to emulate the behaviour. It has the same problem.)
OK, for people who find this and can't work it out, the CSS should look like this:
body {
 color: #111;
 background-color: #3E9C9D;
 background-image: -webkit-gradient(linear, left top, left bottom, from(#fff), to(#3E9C9D));
 background-image: -moz-linear-gradient(#fff 0%, #3E9C9D 100%);
 background-repeat:repeat-x;
 background-size: 100% 600px;
 -o-background-size: 100% 600px;
 -moz-background-size: 100% 600px;
 -webkit-background-size: 100% 600px;
}
#wrapper {
 max-width:960px;
 min-width:840px;
 margin: 0 auto;
}
Edit from 2 years after - the gradient syntax has changed somewhat, and now everyone supports it. Make sure you read up on the changes before using this code.
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