So here's the troubling thing though about de-pressuraztion and other mechanical failure theories...
Posted from CBS news 3/14 8:41 AM:
CBS News' Bob Orr reported Thursday that two communication systems on Malaysia Airlines Flight 370 were shut down separately in the moments before the flight disappeared from radar on Saturday; a data system and two transponders which relayed information about the jet's speed, altitude and location.
While a cascading electrical problem could feasibly cause that kind of staged electrical failure, Orr said it's also entirely possible somebody on the plane intentionally turned off the systems. And investigators say there's further evidence suggesting the jet did not crash immediately after being lost on radar; a transmitter on the plane tried for another four hours to ping satellites. That's an indication to analysts that the jet continued to fly for some time -- possibly as far as 2,500 miles from where it was last detected.
In other words, a multi-system failure that somehow shut down all of the user-accessible tracking/comms devices, one at a time, but somehow left the plane flying for at least another 4 hours and somehow oddly enough manged to not impact the "hidden from view" automatic tracking/comms systems as they continued to function. Anything is possible I suppose, but doesn't sound like the probable answer to me at least.