Symptom
Once an AirPort Base Station (Dual Ethernet) has been configured using the AirPort 2.0.4 in Mac OS X, you can no longer configure that base station from Mac OS 9. If you attempt to do so, an alert box with this message appears:
"The selected base station has been configured with the OS X Admin Utility and can no longer be configured with the OS 9 Admin Utility. Please use the most current version of the OS X AirPort Admin Utility to configure this base station."
Figure 1 AirPort Admin Utility alert message
Solution
AirPort 2.0.4 includes features that are only available when configuring the AirPort Base Station (Dual Ethernet) using the AirPort Admin Utility in Mac OS X.
Attempting to administer an updated base station from Mac OS 9 could lead to unpredictable results. For that reason, AirPort Admin Utility access from Mac OS 9 has been disabled for any base station that has been configured from AirPort 2.0.4 in Mac OS X.
You should use the most recent version of the Mac OS X AirPort Admin Utility to set up an updated base station.