Continuity mistake: The waitress brings Frasier his coffee just as Niles begins to say "Anyway," and she is back behind the counter as he finishes the word. There just wouldn't be enough time in real life to do this. (00:03:55)
Revealing mistake: Towards the end of the episode, as Frasier is on the lounger by the windows, a power cord is on the ground going through the far left window (where glass should be), possibly going to the lamp.
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.