Continuity mistake: Just before Marty says "Quack" to Daphne, his hands are in his lap. The next shot shows them on the arms of his chair. (00:05:40)
Continuity mistake: After Frasier is left alone in the apartment, we can see a glass of sherry and a can of beer on the coffee table, but neither item was on the table when he was talking to the others before they left the apartment. Roz's purse also shifted from the couch to the little glass table during the shot change. (00:21:20)
Continuity mistake: There is a bag of chips on Marty's little table that goes from being open but almost flat to being open much wider and the bag is very rounded, from one shot to another, but no one touches it. (00:18:05)
Continuity mistake: After Frasier passes the pink box with the birthday cake over to Daphne the box is closed. But when the doorbell rings the lid is about halfway open, with no time for this change. (00:04:15)
Continuity mistake: Just before Frasier says "What I want is to be left alone", Roz, Niles, Marty, and Daphne are standing at the door. The shot goes to Frasier, and then back to them, and they have all changed positions, with no time to have done this naturally. (00:21:25)
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.