Thanks very much. I figured out the issue.
It was long and involved, but the only thing that I’ve gotten to work, so…
For anyone else curious:
1. Create div#header-about, div#header-projects, etc., in your stylesheet by copying the main div#header code and changing the background image to suit your needs.
2. Create custom header files (header-about.php, etc.) and replace
<div id="header">
with
<div id="header-about">
or whatever your new div is called.
3. Create page templates for each of your pages (page-about.php, etc). Replace:
<?php get_header(); ?>
with
<?php include (TEMPLATEPATH . '/header-about.php'); ?>
Should work! ?? Worked for me.