If you get information on files and folders in the OS X Finder you will see the access permissions for the items listed at the bottom of the information window.
The items in this list are generally the username of the file's owner, the primary group associated with the owner, and then an "everyone" group; however, there may be situations where the system will not display a group, and instead will show a persistent "Fetching..." notification.
This situation may happen because the system cannot properly identify the group that is associated with the file. In OS X, permissions work by user and group identification numbers being associated with files in the filesystem index, and when you access the file the system looks up these identification numbers in the system directory (the user and group database). There also may be a situation where a user-specific group (i.e., one that is the same name as the current user account) is being used as the default group for a file.
If a username or group is missing, then the system should display something like "unknown" for the respective permissions, but may also continually search for a match and display "Fetching..." while this is under way.
This mismatching may happen after a system has been upgraded, or if you have restored one from backup or migrated it from another system, and generally lies in how the permissions in the filesystem are stored rather than there being a problem with the system's directory setup.
If this is happening to you, then your best bet would be to ensure that your account is associated with the proper group, followed by resetting permissions on your home folder, which can be done with the OS X installation DVD or the OS X Lion recovery partition.
In OS X, local user accounts are members of the "staff" group, with system administrator accounts being members of the "admin" group. To make sure that your account is associated with the proper group, when logged in to your account run the following in the Terminal:
sudo dscl . -append /Groups/GROUPNAME GroupMembership `whoami`
Be sure to change the "GROUPNAME" text to the proper group of either "staff" or "admin," and also note that the "whoami" is encompassed in grave accents (the symbol under the tilde key on U.S. English keyboards) instead of single quotes. When this is done, reset the home folder permissions on your system, the procedure for which will depend on what system you are using:
In OS X Prior to Lion:
- Insert the OS X Installation DVD and reboot with the "C" key held down.
- After selecting your language, choose "Reset Password" from the "Utilities" menu.
- Select your hard drive and then select your user account from the drop-down menu.
- Click the "Reset" button next to "Reset Home Directory Permissions and ACLs."
- Select "Restart" from the Apple menu to reboot normally.
In OS X Lion:
- Reboot and hold "Command-R" to get to the recovery partition.
- Choose your language and select "Terminal" from the Utilities menu.
- Enter "resetpassword" in the Terminal to open the same password reset utility.
- Continue with step three in the instructions above.
Doing this should make sure that the permissions and user/group associations for files in your home directory are based on usernames and groups that are in the user account. Do keep in mind that this will only affect the files and folders in your home directory and not any of those that you have placed elsewhere, such as on external hard drives or within system directories.
Lastly, in addition to ensuring user accounts are set up properly, use Disk Utility to run a permissions fix routine on the boot drive, which should make certain that system folder permissions are also set up so files and folders can be properly accessed. When performing a permissions fix, do not worry about repeated errors in Disk Utility's log window. Just run the fix routine once and then quit Disk Utility.
Some people may find that after fixing account and system permissions that their battery lives might also significantly increase and the system becomes more responsive, as it spends less time resolving group conflicts and more freely looks up group associations.
(Special thanks to MacFixIt reader "Andrew K." for submitting this problem.)