Apple has introduced an updated version of its AirPort Admin Utility for early model (Graphite and Snow) Base Stations.
AirPort Admin Utility for Graphite and Snow 4.2.5 for Mac OS X 10.4 or later software supports the original Apple AirPort Graphite and Snow (Dual Ethernet) Base Stations.
This update provides compatibility for Mac OS X v10.5 or later. The newer AirPort Utility 5.3.1 or later should be used for Time Capsule, and AirPort Extreme or AirPort Express Base Stations.
The 6MB software download is available here.