It depends on the country (and possible on the particular build number). I am checking the latest code, and in the US, 52,56,60,64 is supported under DFS (requires the AP to indicate the channel is safe to use), and the channel 100-140 is not supported. For many other countries, channels 100-140 are supported. It is all set based on what the regulatory group gave permission for at the time of release, which was a while back now.