Airport Express/Airplay problem

Hi, I have just changed my iMac and previously happily used an old Airport Express to play music over Airplay. As the 6.2 version of Airport Utility did not recognise the old device, I purchased a new Base Station model number A1392. Now, I can see the device in my network but when I try to enable Airplay, the name is greyed out and it cannot be seen in the speaker selection on iTunes 11.0.4.

Edit: Well for some reason, it has now recognised the device and is working. I didn't change any settings so it is somewhat a mystery!