Hi,
I had a problem recently with a Group Policy that stopped applying and sections of the policy stopped displaying in GPMC but when editing the gpo the settings were there. In particular the settings were user configuration settings for the site to zone assignment for IE 10. These are user settings applied via loopback processing. I got the policy to start working again and displaying correctly in GPMC by editing the policy (adding a new test site to the trusted zone in the site to zone assignment list). After making this one edit the policy started applying and it also started displaying in GPMC. Strangely enough other sections of the policy were displaying correctly in gpmc when this section was not displaying\applying. I ran gpresult on a few of the servers affected and don't recall if it showed the policy applying or not.
Can anyone help explain this behavior? A few days after it was resolved I was thinking I should have checked which Domain controller I was attached to in GPMC and which Domain controller the servers were connecting to to see if only one domain controller was causing the problem, but I did not do this at the time. We have 3 DCs.
Thanks!