Rick Hauck, the commander of the first shuttle mission after the Challenger disaster, is on MSNBC right now. He is speculating on two theories. What is interesting is the order of his speculation. The first one is not the loss of tiles, but the pitch attitude (40 degrees) on reentry and a possible loss of stable longitudinal control. He further stated that this is controlled and stabilized by small reentry rockets which line the shuttle up in the correct attitude. Unless I miss my guess, this is not a manual input from the pilot, but is done automatically by the onboard systems. I am quite sure that the code will be looked at during the investigation.