To Thine Old Self Be True - S7-E20
Continuity mistake: Niles comes into Cafe Nervosa holding a newspaper and begins to talk to Frasier and Roz. As he says "mere words cannot", the shot changes and the next shot shows the newspaper has flipped over to the other side in his hand. He didn't have time to do this naturally.
Continuity mistake: Near the beginning of the show, Daphne comes home from shopping holding a bag of groceries with the leafy tops of vegetables facing out. Frederick goes to help her and suddenly the leafy tops are facing inwards, without Daphne having time to move the bag.
Morning Becomes Entertainment - S7-E19
Continuity mistake: At the beginning of the show, Frasier and Daphne are talking in Cafe Nervosa and behind them there is an extra at the counter. In some shots he is sitting there doing nothing, and in others he is eating a muffin.
Continuity mistake: Frasier is opening a bottle in the kitchen while talking to his father. He takes the cap off the same blue bottle twice. (00:05:07)
Morning Becomes Entertainment - S7-E19
Continuity mistake: Bebe places her purse behind the couch when she sits down to start the show. It appears and disappears throughout her scene with Frasier.
Continuity mistake: Toward the end of the episode when Poppy is airing her first "arts in Seattle" show, Frasier, Kenny, and Gil convene in the hall outside Frasier's booth to talk. Right after Gil speaks during Frasier's monologue beginning with "I assure you, she is way over her depth here...", viewers can see Poppy through the window sitting at the booth with her mouth closed, looking around (and even up at the ceiling), appearing to be waiting. A split second later, the camera cuts to Poppy in mid-sentence during her live broadcast.
Continuity mistake: In the opera, when Marty waves at the ladies, Fraiser tries to pull his hand down. He looks over at the ladies as he does this, but in the next shot he is turned towards Marty.
Continuity mistake: In the beginning scene, Niles and Frasier are arguing by the door. Right after Niles leaves and Frasier yells "Get out! ", the camera pans out and you can see the entire room, at which point Roz is holding her wine glass in her right hand. Immediately after, the camera cuts to Roz who says, "yeah, some nerve..., " and the glass is now on the table in front of her left hand. There wasn't time for her to set it down (especially across her body), and the camera stays focused on her continuously through both shots.
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.