In FS2002 I created an IFR flight KLAS to KLAX. I take off on runway 25R and am told to turn left to 190. When I get near the green "direct to" line on my GPS which shows that my course heading to KLAX should be 220, I am told by ATC to turn right to 220. Still climbing but holding steady on course 220 (altitude and heading are on autopilot), I am told to contact Los Angeles center. Shortly after doing so, and without touching any controls, my 737 is making a sharp left turn to hold course 220 on autopilot, while my NAV and GPS now show a 270 course to KLAX. If I continue this flight to conclusion, I end up lined up with KLAX runway 25L on a course heading of 300.I have tried the same flight using the default 777 but get the same frustrating results. The only add-on I have installed is MegaScenery for Southern California. I have tried searching the forums to find an answer. The only suggestion I found was to press the "D" key when this happens, which supposedly resets my headings, but nothing happens.Is there anyone else who has had this experience, or knows how to fix this?luvmyFS (but not luving it much right now)

I've had a similar problem. I saw it in both Southern California and in Texas. In my case, the rotation was on the order of 120 degrees.Check your scenery.cfg file in the FS2002 folder. This is a text file which includes an entry for each scenery, including many of the default sceneries. When you get up near 315 entries (the "area" number, not the "layer" number,) strange things start to happen. In my case, I started seeing this rotation, and I also had large areas of the world where things would lock up when I crossed some magical line. Flying elsewhere was perfectly normal.My solution was to "consolidate" multiple sceneries into the same directories by moving files around, and then do some hand-editing of scenery.cfg to cut out the extras and move those high areas down a few slots.I've seen reports on this forum that the number of sceneries you can add before this goes wacky is smaller in FS2004, and one claim that a user has added far more than 315 without problem. Since I'm still flying 2002, I can't answer that myself.

Thank you for your response.I believe that I have just found the answer to this problem over on the MegaScenery forum.Someone over there posted this question:"After installing megescenery SOCAL, all of the nav aids and compass headings are off by 50 degrees. I uninstalled megascenery and the nav aids and headings were correct again. When I reinstalled megescenery I had the same problem, every thing is off 50 degrees. I am using WIN-XP and MS Flight Sim2002. Anyone else having this problem? If so, were you able to fix it?"To which someone else replied:"1. Install the SoCal Update. 2. Delete the file called "longeb.bgl" in the "...LongBe_escenery"folder.It is not needed for FS2002 and is the cause of the problem." I am at work right now but will try this tonight!luvmyFS

Since the Megascenery problem specifically matches your 50-degree rotation, I'd say that's most likely your problem. I don't use Megascenery myself, so I've never seen that one.