Continuity mistake: Frasier is leaving the booth - Roz is standing there holding several tapes in her hand. When the shot goes back to her, she has papers in her hand and there's no sign of the tapes. In the next shot, the tapes are suddenly on top of the tape machine.
Continuity mistake: When Katherine confronts Frasier in the hall at KACL, her purse strap is over her forearm. But when the shot goes to Frasier, from behind her, the strap is over her shoulder.
The Kid (2) - S5-E4
Continuity mistake: After Rick has left Roz's apartment, she goes into the kitchen with the roses and just as she gets there Frasier knocks on the door. Within a couple of seconds she comes back with the roses in a vase, but she just didn't have enough time to do this in "real time".
Legal Tender Love and Care - S8-E6
Continuity mistake: Abbie puts Niles' burning menu in the ice bucket where it remains for the rest of the scene, next to the bottle of champagne. Sometimes the menu is right up against the bottle and sometimes it is an inch or two apart - with no one touching either item.
Continuity mistake: Near the beginning of the show, Daphne drops Martin's eclair into a glass of orange juice. By the end of the scene, the eclair is sitting in a mug. No one moved it during that time.
Continuity mistake: When Niles leaves the bedroom where he thinks he will meet Maris, her lover Shenkman comes in and notices the two roses crossed on the pillow. Once he crosses over to the bed, though, the roses have noticeably changed position.
The Dog That Rocks the Cradle - S7-E5
Continuity mistake: When Roz is working at Frasier's coffee table, she puts a pencil down next to her pad of paper, but when the shot changes, it is sitting on top of her papers.
Continuity mistake: While Frasier, Niles, Martin, and Roz are in Cafe Nervosa, and as Clint comes in, the extra in the background is reading a newspaper, which goes from opened to closed to opened from shot to shot, with no time for her to change it.
Our Father Whose Art Ain't Heaven - S4-E8
Continuity mistake: Martin and Frasier are in the restaurant and Marty says "you're eating light" as Frasier has his menu up at chest level. The next shot, without enough time for change, shows the menu lowered several inches and held at a different angle.
You Scratch My Book... - S2-E15
Continuity mistake: Niles is holding his raffle ticket booklet over its envelope as he picks up Honey Snow's tape. As he says "insightful, isn't she?" the raffle booklet is suddenly under the envelope. (00:01:10)
The Seal Who Came to Dinner - S6-E8
Continuity mistake: Niles gets out some bills to pay for his coffee and puts all of them on the table, one by one. The next shot shows him counting out his bills in his hand again. (00:02:50)
Continuity mistake: Frasier is in Mr. Safford's study talking to him. As Frasier says "a little unconventional," his right hand goes up to his chin, gesturing. As Safford answers, Frasier's hands are grasped together in front of him, with no time for natural change.
Continuity mistake: Just before the closing credits, Marty opens his gift from Frasier - a dressing gown, which he puts back down on top of the box in a disorganized heap. By the end of the scene, a shot shows the dressing gown neatly folded in the box.
The Dog That Rocks the Cradle - S7-E5
Continuity mistake: When Bulldog knocks on Frasier's door, Frasier is sitting on the couch with his arm on the back. In the next shot it is down in his lap as he says "will you get that?" to Niles, but in the next shot it is up on the back of the couch again.
Legal Tender Love and Care - S8-E6
Continuity mistake: Abby orders Frasier out of her office and she bends down to pick up his jacket from the floor, even though it had been on the chair throughout the scene. She then throws it and his overcoat out the door after him - we see the jacket land on the floor and the overcoat on his head. She slams the door and the shot goes to Frasier - the jacket is now draping his head, rather than the overcoat.
Continuity mistake: Near the end of the show, Niles and Frasier are shaping hamburger patties in the kitchen. Niles has a blue bottle of water which sits on the stove top in front of him. In one shot it suddenly appears on the counter to his right; even though Niles hadn't moved it. By the end of the scene it is back in front of him on the stove top.
Continuity mistake: In the last scene of this part of the show, where Frasier is trying to figure out if Cassandra is romantically interested in him - he removes his outer clothes and stands in front of her closet. We see his clothes change position several times. Sometimes they are on the back of the chair, sometimes they are on the floor. His shoes also change places. In fact, the shoes appear to move on their own at one point and are pulled tidily to one side.
The Dog That Rocks the Cradle - S7-E5
Continuity mistake: Roz and Bulldog are sitting on her couch, talking about Baby Alice. Roz has her arms folded in front of her, but in the next shot she is leaning back with her arm behind her and her hand on the couch. The change in shot also shows a change in the position of the toys on the coffee table in front of them. The Tigger puppet goes from one side of the table to the other and the little teddy turns around 180 degrees.
Three Dates and a Breakup (1) - S4-E19
Continuity mistake: Frasier and Daphne are on the elevator; Daphne has a bag of groceries. In some shots several inches of a loaf of French bread is seen, but when she gets off the elevator the bag is sealed up with no bread visible. The bread becomes visible again in later shots as they talk at the door and go into the apartment.
A Midwinter Night's Dream - S1-E17
Plot hole: Niles phones Frasier to tell him Daphne is staying at his place because of the storm. Frasier's phone is in its usual place on the room divider/bookcase behind Marty's chair. After Frasier and Marty leave to rescue Daphne, Niles phones again and Eddie is standing up on a chair staring at the phone. Only problem is, the phone is over on Frasier's desk, where there normally is no phone. If he did have a phone there, it is only a few feet from the other one, which makes no sense.
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.