From PBS' website.
The last signal from the Aircraft Communications Addressing and Reporting System (ACARS) was received 12 minutes before the co-pilot's final words.
The plane's transponder -- which relays the plane's location -- was switched off just two minutes after he spoke, and a few minutes later the aircraft turned back on its flight path.
Yahya said it was not clear precisely when the ACARS system, which sends a signal every 30 minutes, was disabled. Officials had previously maintained it was manually turned off before the final cockpit message.
This just came out in the last 24 hours or so. More egg on Malaysian govt. faces.