pedro2 - the trip with youtube is to begin the download, then go make a cup of coffee, make a sandwich, take a shower or simply browse in another window (which will impede the download of the youtube movie.) But trust me, this will prevent the frustration and stress of waiting for the whole movie to download.
It will run through in stops and starts the first time (while you are doing something else) and then you hit the replay button and enjoy the whole, uninterrupted show.