No, but there are two instances where I came very close. The first was The Exorcism of Emily Rose because it was so dreadfully boring. I was expecting something more like The Haunting or The Exorcist, not a supernatural Law & Order episode. The second was the horrible Land of the Lost movie starring Will Ferrell, because it was so bad it felt like a horrible comedy endurance test.

I managed to make it through both though. Every other bad movie I've seen in the theater was still entertaining enough that the urge to walk out never happened.