For the missing planes, go into your simobjects/airplanes folder and ensure the planes are not hidden in some other directory. For instance, if you used an FS2004 plane with an installer, it would have placed it in Microsoft Games/FS9/Aircraft instead of Microsoft Games/FSX/Simobjects/Airplanes. Also, even if you got it in the Airplanes folder, double check to be sure the actual plane is not inside a second folder. For some reason people like to do that...
For the incorrect pictures, if you mean thumbnails, go into the textures folders and ensure the thumbnails are in the correct folders. Make sure that in the aircraft.cfg file, the titles are correct for the plane you are trying to use, and that the textures are matched to the proper folder...
