Last week, Apple released Airport Utility 6 for OS X Lion. Apple has confirmed that this utility can only configure AirPort devices that use 802.11n.
In a recent review of AirPort Utility 6, it was discovered that it would not configure an AirPort Express. Subsequently, one reader noted that he was able to configure his. Another TMO staff member said he could not. It was a short-lived mystery.
We checked with Apple, and the explanation is that the older model AirPort Express, Model A108x, supports only 802.11 b/g. One must have a newer model, A1264, which supports 802.11n, to configure it with AU 6. This limitation also extends to the older AirPort Extreme without the “n” capability.