Polar SATs

Hello all,I'm currently flying from KORD to VHHH heading 7595N and surprisingly got a FMC Message saying "Insufficient fuel". As I looked at PROG, I saw it estimating 0.0 at arrival. The headwind component is not that significant, so I decided to look at the SAT, and whoa! I got -78ºC. When I checked the TAS, it was at 455. So that's why the FMC is overestimating the flight time. When I checked at "Weather Reports", the SAT at the nearest altitude at the closest station was -48ºC, which is pretty normal and would not cause me troubles.So my questions are: is that normal? If not, what can I do to fix that?Maybe the screenshots can illustrate it better:http://i11.photobuck...seststation.pnghttp://i11.photobuck...ottmann/TAS.jpgThank you!