@Bis47, I guess your "fuel ice messages" reference is to the unverified report on pilotsofamerica.com forum (see
UPDATE on the LHR (Heathrow) 777 incident - Pilots of America Message Board) on 30 January 2008 (and picked up by blogs elsewhere) as to the theories being investigated by the AAIB. One theory the unverified report mentions as being investigated is that:
"Ice in the fuel somehow limiting the fuel flow to the engines. A maintenance message indicating excessive water in the center tank was set during taxi on the two previous flight legs, although it cleared itself both times."
For what it is worth I note that the unverified report was introduced by the words "Aspects that the FAA believes the investigation is concentrating on are: [...]" but also that the alleged fact re maintenance messages is not mentioned in any AAIB statement published to date (whether Statement of accident, Initial Report, Initial Report Update, S1-Report or S3-Report).
Assuming ice in the fuel was being investigated at the time, it seems less likely to be relevant now given the subsequent analysis and AAIB statement in its S-3 Report that: "The fuel has been tested extensively; it is of good quality, in many respects exceeding the appropriate specification,and shows no evidence of contamination or excessive water".
@Peter Brown, you might also have a look at articles re flight in polar conditions at
Aero 16 - Polar Route Operations and on fuel temperature data on polar flights at
http://www.fsinfo.org/FSI-journals/4q_2000.pdf.