a couple problems

recently (after adding some effects without backing up the original folder he..he..he..) I seem to have lost all my lights on the aircraft, default included and the con trail look horrible. just like white painted lines comming from the back of my plane. also when I touch down, lately I've seemed to loose site of the aircraft if I'm in spot view until I move it around abit. ANY ideas??? please help!. thanks. ~Brent