PHP not processed in 4.0.1a

I just got mod_layout and php working under apache 2.0.47 and the headers
and footers are being placed where required.

When I look at the page, the php inside the requested LAYOUT_SCRIPT_NAME is
executed, but the code inside of header.inc.php and footer.inc.php is not
being processed and shows up on the client's machine. Does anyone know how
to solve this problem?

(shortened directives)
<VirtualHost *>
	AddOutputFilter LAYOUT html php
	LayoutHeader /home/httpd/site/include/header.inc.php
	LayoutFooter /home/httpd/site/include/footer.inc.php
</VirtualHost>

For the record:
Apache 2..0.47 (enabled DSO)
Mod_Layout 4.0.1a
PHP 4.3.2