viewtopic.php?f=3&t=5798As you can see, this one has reared its head for me, some time ago, but as I don't really have that much time to fly long haul, i have been able to work around it.
It does appear to be linked to the timer that is used to hold the timings for the log.txt file and the fact that it appears to switch to a negative number somewhere after 6 hours or so, apparently going beyond the capacity of the number variable.
I experienced it using the XP version and don't have the P3D version, but it does look very much like the same issue.
Hopefully, this one will get to the top of the "priority pile" soon, as I have some holidays coming up and a flight from Heathrow to JFK would be good to do.