With the new MacBook Pro's some of you are coming into an issue when adding a printer where the system asks you for an _lpadmin username and password. Apple says, "After updating to Mac OS X v10.5.7 or 10.5.8, (we updated from 10.4.11) you may be prompted to enter the name and password of a user in the lpadmin group when changing a printer setting or printer control." So how can this be fixed? The following are steps to take in the event this issue pops up!
1.) Open Terminal, which is found in the Utilities folder, in the Applications folder
2.) Type this command in Terminal on a single line (or copy and paste this): dseditgroup -o edit -p -a admin -t group _lpadmin
3.) Hit Enter and it will prompt you for your password, enter it (if you dont use a password to login to your computer, dont type anything) NOTE - you will not see the password as you type, but it is being entered
4.) Once you have entered your password, press return. and if successful, it will give you this message, "_lpadmin upgraded to new group format in order to support GUID membership"
5.) If it gives you an Authentication failure, you will need to repeat steps 2-4, and keep in mind the spaces when typing in the command!