Once faced with this issue took me quite a while to figure it out. My customer had a recent AD serve rmigration to Windows 2008. Import users was working fine, but when a new property was requested to be mapped, it wa snot available anymore. See image bellow:
Note: The selection of directory service properties may be disabled if the shared service provider is in an untrusted domain or if profile import is not configured.
Note: The selection of directory service properties is disabled because the portal is in an untrusted domain or no irectory service import is configured yet.
Security Note: If you are using a high privilege account to import, you will be able to read and import directory
How was this solved?
1. Going to Shared Services >> User Profiles and Properties >. Configure profile import
2. Click on the link View import Connections
3. Edit the Import Connection
4. Specifiy a domain controller, picked a random controller,
5. Going back to the edit connection and press Auto Discover domain controller.
6. problem fixed.... totally random... totally worked!
Enjoy!