Re: 2008; Certificate problems

After installing Update 12.1 on some of our computers this error has
continued to plague us.

We are running
 - Exchange 2007
 - Entourage 2008

We get 2 flavors of this error:

Unable to establish a secure connection to <<mail.server.com>> because
the correct root certificate is not installed.

Changes to some setting cause this one
Unable to establish a secure connection to <<IP>> because the server
name or IP address on the server's certificate

I have tried:

1.) sudo certtool i root_certificate.cer v k=/System/Library/Keychains/
X509Anchors
2.) http://www.macosxhints.com/article.php?story=2007082012492012
(was
done already but re-created the profile just in case)
3.)
http://www.themachelpdesk.com/index.php?name=News&catid=&topic=19&allstories=1

One of my users claims this is causing problems because her mail does
automatically come through. This has not been verified by me though so
it could be a different problem.