out of place aircraft and AI - updated

HiMy aircraft is sometimes out of place at major airport terminals, and is surrounded by some AI that are also in the wrong position, sometimes partway through a building.http://forums.avsim.net/user_files/99152.jpgThe aircraft with bright textures in the correct places are scenery objects only. All the AI in the picture are out of position and have dark textures.I have unloaded add-on scenery (Heathrow from the 'British Airports' series is in the screenshot) and reloaded.I am using VFR scenery for the UK and have ensured that 'British Airports' add-on is in VFR mode.The most recent add-on has been World Airports 2, but Heathrow is not one of the airports on that scenery. The same problem does happen at 'World Airports' locations.Over to the experts!RegardsGraeme