citera: After doing some more research on this problem, I came across this post on another forum which indicated this may be a problem with the unknown user on your OS X system. The unknown user is one of those hidden Ids, like root, that has special UNIX functions.
Eric Wing (another Helper) and I developed the following procedure for checking and recreating the unknown user if yours is missing.
Verify the existence of the unknown user:
There are two ways to check your system to determine if the unknown user is missing:
A. With NetInfo Manager
1. Open NetInfo Manager (in the Computer > Mac OS X > Applications > Utilities folder)
2. In the middle column of the resulting window, select (click once) on users.
3. The column just to the right should fill with the list of users. See if unknown appears in the list.
B. ´Get Info´ method
1. Select any file, preferably one you own (otherwise you´ll need to authenticate first).
2. Perform a Get Info (Command+I or Apple+I) key combination on the file.
3. Select the disclosure triangle for Ownership and Permissions panel.
4. Click the Lock icon.
5. Click the double arrowhead next to the "Owner: owner_name" field.
6. In the resulting list, unknown should appear in the list of potential owners.
To recreate the unknown user:
1. Open NetInfo Manager.
2. Click the Lock icon in the bottom left hand corner of the window to authenticate, and authenticate.
3. In the middle column, select users. The column just to the right should fill with the list of users.
4. Highlight/select nobody
5. Under the Edit menu, select Duplicate; or press the key combination Command+D (Apple+D). This will create a new user, nobody copy.
6. Select the newly created user, nobody copy.
7. In the bottom half of the split screen, you´ll see Properties and Values for ´nobody copy´. You´ll need to edit some of the Values for ´nobody copy´ to make them what they should be for ´unknown´ -- this will "convert" ´nobody copy´ into ´unknown´. ´unknown´ has the following values:
Property Values
expire 0
realname Unknown User
name unknown
passwd *
uid 99
_writers_passwd unknown
change 0
shell /dev/null
home /dev/null
gid 99
8. The following properties will need to have their values changed: realname, name, uid, _writers_passwd, gid. So double-click on the Values for those propteries and edit the contents with the values for ´unknown´ above.
9. In the menu bar, select Domain > Save Changes.
10. Agree to Update the copy of the database if you´re sure of your editing.
11. You should now see that nobody copy is now unknown
12. Quit NetInfoManager.
You should probably Restart at this point.
