Godfather - missing subtitles?

[stigdu]

I just watched my Godfather part 1 DVD today, and noticed that during the restaurant scene between Michael Corleone, Sgt. McCluskey and Solazzo, there are no English subtitles for when they talk in Italian. Do I have a faulty disc, or are we not supposed to know what they are saying to each other?
I'd forgotten just how brilliant this film was.