Continuity mistake: Frasier is in the kitchen pouring mini chocolate chip cookies from a bag into a bowl while talking to Daphne. The motion of him pouring (and the sound) doesn't stop while he talks but when the shot changes the bag is on the counter next to him.
Continuity mistake: While Niles, Daphne, and Clive are sitting on the couch talking, the large book on the coffee table goes from closed to opened during the scene, even though no one touches it.
Continuity mistake: When Clive arrives at the apartment, he puts his coat over the front of the arm of the couch. As the scene progresses and Marty tells him about being an astronaut, the coat is suddenly on the back of the arm of the couch, even though no one moved it.
Answer: It equals the record of James Arness of "Gunsmoke" for the actor who's played the same part on TV NOT in a soap opera. If you include soaps there are two main contenders - William Roache, who's been playing Ken Barlow in "Coronation Street" in the UK since 1960. Don Hastings has been playing Robert Hughes in US soap "As the World Turns" since 1960 as well.