I was passing channels today at noon when I saw Kramer (well the actor, not Kramer) in a movie in WTBS. The movie is from 1982, "Young Doctors in Love" with Sean Young. It's one of those "Police Academy' type of movies about young doctors in training at hospital.
Kramer (well, the actor) is shown being confused for an operation he didn't have to have. He acts just like he does in Seinfeld. Maybe that is the way the actor really is! and he's just not acting in Seinfeld.