exim not acting on SpamAssassin config

Hi,

I have having problems with sa-exim running on debian. When email is  
scanned by sa-exim the settings in /etc/spamassassin/local.cf do not  
have any affect on sa-exim. If a file is scanned by spamc manually  
the setting are used.

For example, this line in : etc/spamassassin/local.cf
version_tag spike1

Here are some of the headers from an email scanned by sa-exim:
X-SA-Exim-Connect-IP: 127.0.0.1
X-SA-Exim-Mail-From: [email protected]
Subject: sa-config
X-SA-Exim-Version: 4.2 (built Thu, 03 Mar 2005 10:44:12 +0100)
X-SA-Exim-Scanned: Yes (on spike)

sa-exim seems to completely ignore my settings. What have I done wrong?

Thanks,

Paul