The Firemen's Ball

Czheckoslovakia, before it was broken into bits was where this movie was filmed. The same country banned the movie from showing in its theatres when it was released. I don't know what is so bad about the movie, there is nothing contreversial in the film, it just revolves around a night when the firemen stage their annual ball in town. Maybe the communist government was just paranoid? It is from the director of "One Flew Over the Cuckoo's Nest" and "Amadeus", Milos Forman. Though I couldn't really understand what was so great about this movie. Maybe the ban in its country of origin and the Milos Forman tag I s'pose?