Over the last few days I've noticed that if I start a movie (which contains an advert at the start), it plays the advert fine, then plays the first second or two of the film then the 4 circles spin around until you press the back button.
Sometimes you can then restart the movie and it'll pick up where it got stuck and everything will be fine. Other times it will play a different advert and then spin around again.
Hope I've explained that well enough? Anyone else had similar experiences?