If you’ve been having problems with an AirPort Extreme-connected hard drive and Apple’s Time Machine feature, you’re not alone - turns out a lot of us have been afflicted by the bug.
What takes place: You connect your drive, set it up using AirPort Utility and begin to save those valuable Time Machine files for back-up, recovery and data protection. It all goes swimmingly, and then you install AirPort 7.4.2and a few hours later, your drive stops working. You can’t even access them using the Finder until you reboot your AirPort Extreme. And then, it only lasts a few hours and you must reboot all over again. Annoying
MacOSXHints h