Hi!Sorry to bring up quite an old topic but I have just got the PMDG 747-400 for FSX and am currently flying from LHR to JFK and am experiencing the same issue as you are describing. I don't have a registered version of FSUIPC, but am flying with the weather set to 'Clear Skies' and wind velocity is 0. The aircraft is gently banking a few degrees right then a few degrees left every couple of minutes. Like you, I've only noticed it whilst flying over the Atlantic (ie with no close navaids). It's like it's continually trying to track the route.It's certainly not as bad as the problems I was having with 757 Captain (where the AP frantically shook the aircraft left and right violently), but if you were a passenger on this aircraft you'd be reaching for the barf bag after a while!Thanks,Tom Wright