Office 2003 SP3 failing while using auto-updates

I am willing to deploy this service pack out across the various networks I support, but I have machines failing the auto-update process left and right.

Even if I manually visit update.ms… the update will tend to fail.

However, if I manually download the SP3 installer and then manually run that installer on each local machine the update succeeds.

Is anyone else seeing this kind of behaviour? Is there a forum out there where this is being discussed?