a couple of days ago I was flying from EDDF to EGLL, real world weather turned on. I am also using FSUIPC. Well anyway, it was a bloody scary flight, too much turbulence for my taste ;-). When I was doing my ILS approach, ATC cleared me and I had to maintain 2100 until established on the localizer. I also calibrated my altimeter correctly to the value ATC gave me. When I intercepted the glideslope, I was wondering why I was so ##### low. Pressed "B", and suddenly I was at 1600 and not 2100 any more!!! What can you do against those huge pressure changes between two close regions, shouldn't FSUIPC smoothen them anyway? Or is there a way to make ATC give you the correct QNH value for the destination airport?