I think James Cameron's "The Abyss" is kinda famous for having way more funny moments than intended.

I saw it in the cinema for its recent anniversary re-release. As you might expect most of the audience were enthusiasts and tended to lean older-male and slightly "technical" or "nerdy" in interests/professions. All to say that they were taking the film seriously. But then there were some, a minority, who didn't fall into that demographic at all. They found many moments in the film hilarious and were laughing out loud. Which rather annoyed the majority of the crowd some of whom would look around wondering where the annoying laughs were coming from. What's interesting is that over time the majority softened and started to find the humour themselves and laugh out loud at similar moments.

This is also mentioned in the wikipedia for the film ... it seems under the strain of making that movie some of the directing just got a little comical.