I recently did a complete reinstall of FS9 and the PMDG 737. I should also add that I have the registered version of FSUIPC.Although I haven't yet tested all systems (VNAV, LNAV, etc.)the one thing I have noticed so far is that when I set a certain heading for the plane to hold say 65 degrees for example it settles on something more like 62 degrees and just hold's there.The funny thing is that when I go into spot plane view for example the FS data at the top of screen indicates that I am in fact heading 65 degrees. So I don't really understand what is happening here.

Mr/Ms Nameless,You are experiencing cross winds.Hope it helps,

No it's not that because I use customized weather with wind speed set at zero.Mark

Mark,That puts things in a different light. Care to share a screenshot? I'm thinking it might be a mag/true heading error. Any add-on sceneries installed as well?Hope it helps,