jthwalker

I'm trying to do a 10 hour flight, created a flight plan in fsbuild, and imported it into the fms of the PMDG 747. after about 30 minutes the 747 started veering off the flight plan and making random s curves. I thought it might be because of sharp tight curves fsbuild had put in it, so I deleted the departure waypoints, and it soon had a nice long line and was following it fine. about 30 minutes later, it started making s curves again on either side of the acars map. What gives? I would presume that the 747 would be like every other aircraft, and simply follow a straight line. Am I doing something wrong here, or is this a known issue? 10 hours is a long time to sit here and baby a 747 with the heading indicator... Everything else is working just fine, so it's not an FSPasengers failure. Any ideas?