"I DO NOT believe these fuel theories, for one reason and one reason alone... I cannot believe that in the 10 (or 12) years that the 777 has been in the air that this is the first occasion that this has happened."
I was flying a 747 that morning across Russia and Germany, landing in LHR at 0500am from the Far East. I have never had to decend to a lower FL in order to increase my fuel temperatue in 25 years of jet flying. That particular morning I had to go down for the last hour of cruise to FL250 before my fuel temp began to warm up. Every other jet in my vicinity that day also decended for the same reasons and some were unable to decend as low as requested. IE Qantas, Malasian and Thai Air) There was an unusually cold air mass over S Russia and Germany that day so it could well have been the cause of the 777s problems.