ok i just saw the directors cut, and it really shed some light onto a lot of things. but there is still one thing i dont understand, tha tangent universe was created when time became corrupted, so when the engine travelled back through time, however at the end, back in the real universe the engine still falls into donnie darko's room, doesnt this mean that time is corrupted, also the plane crashed because of what happened in the sky when the tangent universe ended, so in the real universe which would continue normally, the plance shouldnt crash and the engine shouldnt be sent back in time. everyone following me?

the first indicator that time is corrupt is the appearance of an artifact (the jet engine) and a living reciever (donnie darko) is chosen to try to make sure that man continues to live on in hte real universe, the living reciever suffers horrible nightmares and hallucinations, and can visulise the 4th dimension. So at the end, is it another tangent universe with a different living reciever, or is it the main universe?