I have purchased/rented a movie (SD) and it is not playing... I have downloaded 1GB and the alert "ready to play" does not appear. Besides this, a doubleclick opens the Quicktime window and the player icons, but the movie does not start. The correct time is displayed and when I scroll the timeline I can see the pictures, but the play-button does not start playing the movie... I have the same problem with another movie :-(
EDIT: I used the native Apple iTunes Store (is there any other store?!)