Surely doesn't happen here and that's not supposed to be happening. Are you still using FSX SP2 perhaps ?
There as still some bugs left in it with rotated objects, which has been fixed in FSX+Acceleration Pack or FSX:SE but, unfortunately, nobody is going to fix them in FSX SP2.
You can TRY resetting your FSX.CFG to default, this might possibly caused by a tweak or a setting that is not right for your system. To reset the FSX.CFG to default, remove (or move to a different folder, to keep a backup of it) this file:
%APPDATA%\Microsoft\FSX.CFG
Then start FSX and it will build a new one with all default settings. Apply ONLY the HIGHMEMFIX=1 tweak, and nothing else.
Then, after the FSX.CFG has been reset, you'll have to reinstall the scenery, otherwise nothing will work, since it will have to add its own path for Simobjects. There are also other addons that might require their own SimobjectPaths in the FSX.CFG, like SODE or UT2, which will have to be reinstalled.
If you know how to edit the file manually, you might take the existing SimobjectPaths lines for your OLD FSX.CFG, that's why it would be best making a backup first and/or moving it to a different folder, instead of just removing it.