Mac OS X 10.3 Panther: Fast User Switching Issues

Over the past few days, we've covered a few issues with Fast User Switching in Panther, including issues with backup utilities, scanners, and the "cube" visual effect. We've been discovering, and readers have been reporting, other issues, expected or unexpected, that are experienced when using Fast User Switching. Below is a list of a few of these issues:

"Cube" effect not appearing Yesterday we mentioned that one common cause of the vaunted "rotating cube" effect not appearing -- when switching between accounts using Fast User Switching -- is an older video card. We've since received a number of additional potential explanations, from a number of MacFixIt readers.

One such reason is if the account being switched from and the account being switched to are set to use different display resolutions, color bit depths, and/or refresh rates. In these situations, Panther evidently forgoes the rotating cube effect and instead simply fades between the two account displays.

Another reason, according to reader David Butler, is that some video cards may not be able to support the effect at extremely highest resolutions, even if they are "supported" cards that are able to show the effect at lower resolutions.

NetInfo Login issues Reader Dov Cohen describes an issue using Fast User Switching in a NetInfo/Workgroup Manager environment, in which users' Home directories are stored on a server rather than on the local computer:

"We have a Jaguar Server set up with Netinfo/Workgroup Manager enviorment. User's Homes are stored on the server, and they can move from one machine to the other maintaining their settings. You can pick 'Other...' in the login window, type in your short name and password, and vuala - you're in (well, that's the whole point of WG Manager). That's the good thing. After installing PANTHER, once logged into a machine via your network account, you can use the Fast User Switching menu to go back to the login window. Then pick "Other..." and type in another network login name and password, you'll immediately get an error 'Logging in to the account failed because an error occured. The home folder for the user account is located on an AFP or SMB server. Contact your system administrator for help'."

iTunes pauses/stops If you're listening to iTunes in one account, and another user is "switched to" using Fast User Switching, iTunes will pause. Considering that the other user would have no way of stopping iTunes in your account, we consider this to be a nice feature.

On the other hand, if iTunes is running in one account, no other users will be able to run it. They'll receive an error that "You cannot open the application 'iTunes' because another user has it open. Ask the other user to quit the application, then try again." We consider this to be an not-so-nice feature. (See the "Classic Environment" entry, below, for a way to get around this if your account has admin privileges.)

QuickTime Player preference Related to the previous item, QuickTime player has a preference -- "Fast User Switching: Pause movies when logged out" -- that provides the same functionality. If you don't enable this feature, QuickTime Player will continue to play during a user switch.

iChat disconnects If you are logged into AIM/iChat/Rendezvous and your or another user switches to another account, iChat will automatically log you out. However, once you switch back to your account, iChat will automatically log you in again.

Classic Environment can only be used by one user at a time If another user has launched the Classic Environment in their account, and you then attempt to launch it when logged into your own account, you'll get an error that reads "Classic cannot start because it is already running. Classic is being used on this Mac by the user 'username'."

If you are an administrative user and you need to use Classic, you can use Terminal to force the Classic Environment to quit. You can also launch Activity Monitor, switch the "Show" menu to Other User Processes, and then quit the "TruBlueEnviro" process. You will then be able to launch Classic in your own account. Note that both of these methods may result in the other user -- the one who was running Classic -- losing data if they had unsaved changes in Classic applications.

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