One of the recurring elements in the series is Tony watching TV as reflection or foretelling of his criminal acts. It's always a show about WWII. At some point he tells Melfi that he's not going to hell because he's a soldier, he follows codes, etc. So, him and Sil going to watch a movie about WWII makes perfect sense.
The only problem is, it's Sands of Iwo Jima, not Iowa Jima. So the question is, was this:
1. A simple misspelling no one caught?
2. A copyright thing?
3. A purposeful misspelling?
I'm leaning towards 1, but thought I'd post this up here in case anyone has a better idea. It could be purposeful. Maybe the message here is that Tony isn't really a soldier. He tries to play the part but really has it all wrong because he's just a crook. Dunno, thought it was interesting (or amusing ;)).