Continuity mistake: During the scene when Marty and Daphne are in the car going to the shoe store, she stops at a red light, as does the black car on her left. During the shots that follow, the car on the left, although always black, is a different car in different shots.
Continuity mistake: Frasier and Niles are in Cafe Nervosa - we see Frasier put his coffee down but as Niles says "Spanish leather", we can see Frasier's cup up in the air again on the right - with no time for the change.
Continuity mistake: Just before Eddie drops his master's slippers by his chair, Marty moves his cane over to the other side of the chair. The handle is facing outward, but when the shot changes, it is now towards the couch, even though Marty didn't touch it again.
Continuity mistake: When Frasier is in the men's room crying to Frasier about Sharon, he has toilet tissue in his hand which sometimes is bunched up and sometimes is hanging about 10 inches down, even though he never changes it.
Continuity mistake: When Daphne mentions she had a dream about a gymnast, she is looking at Frasier, but a quick shot change and her head is turned 180 degrees looking at Niles. This couldn't have happened in real time.
Continuity mistake: Niles and Frasier are looking at books trying to figure out Frasier's dream. When Daphne and Marty come in the door, the shot shows that the book that was on the end of the table has moved quite a distance and is now in front of Niles.
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.
Audio problem: As Frasier says, "Well, let's shoot it to the news," we can see his reflection in the booth, but his lips aren't moving as he speaks.
Continuity mistake: Martin goes out to a baseball game with a famous writer that Frasier and Niles admire. While he is out, they read one of his books he accidentally left behind. When the author returns, he ends up holding the pages of the book in his hand, whilst standing in front of the fireplace. In one shot he is holding them in his left hand, but when the view cuts to another angle, he has them in his right hand. This occurs just before he goes outside to throw the pages off the balcony. (00:20:25)
Continuity mistake: When Bulldog is telling Roz and Niles about Reggie, Roz is partially facing him with papers in her hand - in the middle of his sentence she is suddenly at the keyboard, without the papers, with no time for normal change.
Continuity mistake: A fan next to Niles is holding his nachos container by its side as they talk. In the shot where he gets up to leave, his hand is under the container, with no time for this to have happened naturally.
Continuity mistake: While Marty and Daphne are watching the basketball game on TV, he says "it's completely different", the remote suddenly appears on the table beside him; it wasn't there before and wasn't in his hand. A couple of shots later, when he yells "unbelievable!" it's gone again.
Continuity mistake: When Martin first finds out how Niles cured the basketball player, Niles is getting a drink, and Martin is in his chair. During the shots between them, the remote control on the table next to Martin instantly rotates between angles at least twice.
Continuity mistake: Marty throws his coat on the stairs, but it moves to the landing.
Continuity mistake: When Lilith and Frasier are at Dr. Campbell's (the first time), he makes them tea. A shot shows him preparing it, pouring it, etc. But in the next shot, Frasier and Lilith are already holding their cups. There was not enough time for him to have passed them the cups.
Continuity mistake: Frederick appears in the kitchen to talk to his parents, who are ignoring him. In one shot he is covered with spots and in the next, he only has about half as many. He is supposed to have hives, which I know can appear and disappear quickly, but these look nothing like hives in the first place.
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.
Dad Loves Sherry, the Boys Just Whine - S4-E9
Continuity mistake: When Sherry brings in the bottle of wine, it's in a paper bag which is twisted around the bottle when she puts it on the coffee table. The next shot shows the bag has been loosened around the bottle and is quite wrinkled. No one touched it in that short time.
Dad Loves Sherry, the Boys Just Whine - S4-E9
Continuity mistake: When Sherry first meets Frasier and Niles, she puts her coat down towards the center of the couch. A few shots later, although no one has moved it, it shifts to the left and her purse, which wasn't visible before, can be seen.
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.