Audio problem: Near the start of the show, Frasier is in the booth at KACL, and has told Roz off and is glaring at her through the glass. As the shot shows her face, however, we can see the reflection of Frasier in the glass - he is smiling and his lips are moving as though he is talking. However, there is no audio to match his speech.
A Word to the Wiseguy - S3-E15
Audio problem: Around the time when Niles is talking about "wealthy white women," there is a shot when his mouth is moving but there is no sound coming out. It then suddenly changes to a shot when you can hear what he is saying. (00:02:15)
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.