When I acquired a second printer dedicated to making prints and photos, I decided to dig the older Airport Express I have out of a drawer and set it up to be a wireless print server for that printer. However, I ran into a bit of a snafu: the older Airport Expresses require AirPort Utility 5.6.1 to run. It's still available on Apple's website, but even though it's easy to obtain, you can't run it in Mountain Lion.
The actual AirPort Utility 5.6.1 software runs just fine on Mountain Lion. Its installer, however, isn't compatible.
