Replying to Problems with dvd quality

ok, so i made my movie on final cut express, and used quicktime conversion to put it on i-DVD...but when i burn it the quality sucks, I've even tried making it HD quality which took almost a day to load, and the quality is like sketchy and everything seems spasmatic, and whenever there is fast action the skiers have lines through them.

does anyone know how i can fix this and make the quality better? any help would be great, thanks