Revealing mistake: When Frasier drives into and breaks the barrier at the parking garage, you can see that the barrier snaps very cleanly at an obviously pre-cut point.
A New Position for Roz - S10-E24
Continuity mistake: When Niles and Daphne are at Cafe Nervosa, the empty coffee cup on their table changes position frequently between shots.
A New Position for Roz - S10-E24
Continuity mistake: After giving his speech at dinner, Gil gulps down his glass of wine. In the next shot the glass is suddenly half full again.
Continuity mistake: After Frasier watches the video of Eddie, he tosses the remote on the coffee table. When Niles comes in a short time later, the remote has disappeared, but when Niles asks, "Aren't you going to ask me what's up?" we can see the remote again, on top of the manila envelope. It disappears and reappears throughout the scene.
Continuity mistake: During the opening credits, Roz and Ann are sitting in Cafe Nervosa - just before Roz says "Frazier" we see Ann put her mug down. When Frasier approaches, we see her put it down again.
Continuity mistake: When Frasier's new agent is at his apartment explaining how Frasier could take advantage of the crane incident, the remote on Marty's table rotates about 30 degrees, even though no one touches it.
Adventures in Paradise (1) - S2-E8
Continuity mistake: When Frasier is first looking at the magazine article featuring Madeline, we can see the page opposite the one he's looking at. The next shot shows a different page, even though he is supposedly looking at the same one, all the time exclaiming about how great she is.
The Dog That Rocks the Cradle - S7-E5
Continuity mistake: During the opening credits Roz and Frasier are sitting on his couch working. Roz is telling him that she has a date the next day - he is holding a magazine. But as she says "a month", the shot goes back to Frasier and he's holding papers rather than the magazine.
Continuity mistake: During the scene where Daphne is upset because there's a spot on her dress, Roz is standing with her arms by her sides - then in a quick shot change, her arms and hands are up in front of her, holding her purse and wrap.
Continuity mistake: When Dr. Nora's mother comes into Nora's booth, she locks both doors so Frasier can't get in. However, Nora gets upset, quickly gets up and opens the door, without having to unlock it.
Continuity mistake: This is a mistake within a mistake: Niles and Frazier are trying to get the wrapped presents out of F.'s apartment and replace them with others, to play a trick on their dad. They are getting completely mixed up, and presents are being taken out and then returned by mistake, mostly by Frasier. At one point Niles has a pile of gifts which he puts down on the table behind the couch - the shot shows him holding them, but the next shot shows a completely different pile of presents, even though it is supposed to be the same pile. Frasier picks this pile up. It soon changes again in the next shots.
Ain't Nobody's Business If I Do - S5-E11
Continuity mistake: Frasier and Niles are looking at the report the private detective gave them on Sherry - Niles is holding one sheet apart from the others but as he says "it does bode well for Dad", the papers are all together again, with no real time for this to occur.
Three Dates and a Breakup (2) - S4-E20
Continuity mistake: While Frasier and Marty are in the kitchen arguing about Sherry, his can of beer moves from the right side of the counter quite a distance over to the left of the dishes he broke. The sugar bowl and jam pot also change positions during the same shots.
Continuity mistake: Frasier is holding a plate of food in the kitchen, but after Roz comes in with the exploded cherries jubilee all over her, the food on his plate has changed completely. It could not have been affected by the cherries jubilee explosion as he had his back to the door when that happened.
Shutout in Seattle (2) - S6-E24
Continuity mistake: After Bulldog loses his job he goes to Roz for a hug. He puts his right arm around her upper arms but the next shot shows his arm around her shoulder, with no time to have shifted naturally.
Continuity mistake: When Niles goes to take off his pants he looks over at Eddie who is sitting on the right side of the armchair. The next shot shows Eddie getting out of the chair and onto the footstool - however, he is climbing out of the left side and he had no time to shift position. (00:01:55)
Continuity mistake: When Frasier and Niles are in Donny's office, in some shots his towel is next to his briefcase, in others it is on top of the briefcase. (00:04:40)
Continuity mistake: When Frasier is offering to help Lorna carry her books, her purse switches from her right shoulder to her left arm and back to the right from shot to shot.
Continuity mistake: Near the end of the show, Dr. Nora's mother is chasing Nora through the corridors of KACL, behind the windows of Frasier and Roz's booth. We can see them go by, from window to window. The shot then cuts to Frasier, looking horrified, and we see Nora's mother run by a couple of windows again - even though this could not possibly have happened in real time.
Continuity mistake: When Frasier and Niles are in the restaurant, Niles is under the influence of medication. He lays his head down on his arm just as one of the geniuses arrives and greets them. In the next shot, his head is lying right on the table, with no time for him to have switched positions.
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.