Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Apple TV updated with Bluetooth Keyboard Support
iOS 6.1 has just been released for more carriers on LTE, Siri movie ticket purchasing and other updates, however Apple today also updated Apple TV, bringing Bluetooth keyboard support, Up Next, and an enhanced iTunes in the Cloud service.
The first release of the iOS 6.1 beta was back in November and no GM version was released prior to today’s announcement which is slightly strange, but now, not unheard off! The update also includes redesigned music controls and new MapKit framework enhancements.