Theora Movie Lag?

Um... Yes, I am having the problem of lag when I set the video. I heard from another post that others had this problem, but I am having trouble of finding any post about this. Oh, is their ANY control for loop? Because I made my own, but it gives a flash every time the movie is done.

(P.S. I would vary be appreciate if someone answered me how I can get rid of the lag soon.)