Two identical Vista machines, only one processes Group Policy Registry Extension

I have two Panasonic Toughbook CF-30 machines setup from the same installer CD. Both machines were joined to the domain and moved into the same OU. Both machines have no errors in the event logs on startup. One machine gets the ‘AutoLogon’ group policy which contains the registry entries to get Vista to autologon, the other machines does NO registry processing from any policy that has registry settings.

The working machine logs Event ID 4016 from GroupPolicy which says ‘Starting Group Policy Registry Extension Processing. List of applicable policy objects: (No changes detected.) AutoLogon Policy’

The other machine does not have any events which mention registry processing.

Any pointers on where to dig / what to try next?

Stumbled across this article:
http://blog.mpecsinc.ca/2009/05/vista-service-pack-2-not-applying-group.html

Installed KB943729 and now the registry settings are being applied.
Software Update Services says this update is ‘installed/not applicable’ to the Vista machines, but manually installing it fixes the problem.

Check more discussion of this question.

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