I see that Vattallu has responded to this question by quoting the relevant document, it should be stated that this issue is being seen on access points with firmware 15.2(2) and that the status tab on the 2.4 interface is showing Transmit Power error.
Should the maximum power within the ETSI area not be 20dBm utilising three antennas?
In the last month we have seen a minimum of 20 access points on this firmware level exhibiting the same issue, and once firmware level 15.2(4) has been applied we see a maximum of 18dBm on transmit power and a further issue of not being capable of changing the Client Power parameters!!!!
It zeros out with no level configured therefore no local, 9, 12, 15 or 18dBm selected.
Jamesm