Flightplan problem

[Guest fsfan]

Hi there...Yesterday I started a flight from LFPG to HECA but I was not able to fly the whole route at once. I saved the flightplan in the FMC and the flight in FS9.Today I wanted to continue the flight, so I loaded the saved flightplan in the FMC, reprogramed the ZFW, Block fuel, CRZ Alt... and was able to continue the flight. At least for some time.About 10 Minutes in on the resumed flight, the plane started to turn off the route displayed on the aircraft systems (NAV Mode engaged). I tried to investigate why this happened and noticed that the Track to the next waypoint which was for example 120 a few minutes before had changed to let's say 070 which explains the plane started to turn. I have to add that the waypoint mentionned was still added of my plane by at least 20 miles. From there on I had to continue the flight with HDG selected.Do you have any ideas on why that happened or how this can be solved ?Before posting here, I tried to reload the situation, and the same thing happened but never exactlly at the same place. And once, the 3 or 4 next waypoints dissapeared from the flightplan and the next waypoint on the flightplan was the 3rd or 4th away from the actual position of the aircraft. Here also do you have any ideas or suggestions ?Thanks a lot in advance for any help or advice.RegardsStephane

[Guest NormanB]

Once loaded did you do DIR -> the next waypoint?Is it possible that the aircraft was simply trying to fly back to a waypoint behind your present position?