Apple released AirPort Utility 5.3.1 on Tuesday as part of its AirPort Base Station Update 2008-001. The update requires Mac OS X 10.5 or higher and include includes fixes and compatibility improvements for AirPort Utility, AirPort Disk Utility and AirPort Base Station Agent.
Apple states that AirPort Utility 5.3.1 is intended for setup and configuration of the AirPort Express and AirPort Extreme Base Stations as well as Time Capsule. The update is free and available via the Software Update application, or as a downloadable installer at the Apple Support Web site.