Breaking my head with this issue for the past 2 days!

Received Access Denied error in SPD so tried to set Meta Data permission and get the following error.

1. I am one of the Admins for BSC service Applications

2. I belong to Farm Admin Group

3. I have required permission in SQL

4. Tried opening CA in Admin Mode (IE -> Run as Administrator)

5. ULS Logs shows the following

   Access Denied for User '0#.w|domain\skumar', which may be an impersonation by 'DOMAIN\skumar'. Securable IMetadataCatalog with Name 'ApplicationRegistry' has ACL that contains:

Any more ideas? please let me know if you need more information.