The early reports stated that the AC lost radar contact at "cruising altitude".
The weather reports state no T/storms or anything unusual in the area.
No distress signals were transmitted.
If the flight had indeed landed at a diversion airport it would surely be standard procedure to inform air traffic control that they were heading there.
The whole thing seems a bit odd, with all kinds of conflicting information and speculation, and at this stage it's sounding a lot like the Air France flight that stalled at high altitude, and went down over the Atlantic a few years ago,
I blame the Americans......and Thaksin.