Login window choosing which accounts to display

Hey all, finally got all the machines to successfully talk with my Xserve. After adding twenty or so accounts, everything was going swimmingly. Then I created a separate group and started moving accounts around. Here's the general overview of what my users list looks like: Intro Class: (no members) Advanced Class: (no members) Board Members: A B C D E F Music Staff: A B C G H I ... DJs: (no members) For some reason, whenever the login window refreshes its preferences, only accounts A, B, and C are displayed in the list (in addition to the local administrator). Prefs are set in WGM so that all groups can access the machines. Logging on as the local administrator no longer presents the option of enabling/disabling workgroup management. Logging on and then logging off does not restore the login window to its proper state. Only by deleting the mcx_cache from Netinfo or by rebooting the computer (something non-administrators cannot do) does the login window restore itself, only to screw itself up again if left idle for a duration of time. Our regional Higher Education account exec happened to be in today, and he noticed that this happened when the machine did anything energy-saver related. So we disabled all sleep functionality, including monitor sleep and dimming of the monitor. Didn't fix the problem, just made it really easy to duplicate. Anybody have any idea why the login window would choose that only members of both the Board Members and Music Staff groups would show up? Changing the login window to a username/password window is a functional workaround for now, but is an unnecessary complication of the process.