Continuity mistake: Frasier is having a glass of sherry, sitting on his couch, talking to Niles and Martin. As Marty says "let's go have dinner", Frasier throws his hands up - in real life he would have still had the sherry in his hands. There was no time for him to have put it down.
Continuity mistake: When Niles, Roz, Marty, and Daphne are in the living room confessing something shameful, Martin says, "Every time I watch 'The Sound of Music,' I cry." As the shot changes, we see that his hand goes from his arm rest to his lap and his beer can goes from being on one side of the remote to the other.
Continuity mistake: In the scene where Daphne, Niles, and Frasier are at the table trying to solve the old murder case, the string and paper tag on Daphne's teabag changes sides in her mug.
Continuity mistake: When Frasier is reading from the psychiatric journal that contains Niles' letter, at one point he is holding it in both hands by the front cover - the shot changes and he has one hand on the front cover and one hand on the back cover, without time to switch naturally.
Three Dates and a Breakup (1) - S4-E19
Continuity mistake: Near the start of the show, when the waitress gives Frasier the tickets for the show, she has a dark blue dish towel over her left arm, but as Frasier walks away, it is no longer there.
Continuity mistake: During the breakfast scene Marty's cane is leaning against the table in the same spot, but sometimes there is a bowl of lettuce next to it, and sometimes a bowl of cheese.
Continuity mistake: In the scene where Frasier and Niles are talking in Cafe Nervosa, the position of Niles hands and arms change a couple of times. At one point, while Frasier talks about the young woman he has met, Niles folds his arms in front of him but in the next shot to Frasier, we can see Niles fingers laced together - and then the shot returns to Niles with folded arms. They stay this way until another shot where he says "You were in a mall?" and his hands are suddenly on the table and one is lying over the other.
Dark Side of the Moon - S7-E22
Continuity mistake: When Daphne goes to Niles's place to see him, she sits down on the couch and slides her purse behind her. A couple of shots later Niles gets up and now we can see her purse on the couch to her left. At no time did she make any movements that could explain its change of position.
Continuity mistake: Throughout the Christmas parade we can see that the headphone/microphone is on the left side of Frasier's head. During the first break just after one of the crew members is telling Mary that her improv is really good he tells Frasier to lighten up. Just after he says this you can see that the headphone/microphone is now on the right side of Frasier.
You Can Never Go Home Again - S3-E24
Continuity mistake: Roz has a cassette in her hand as Frasier says "call-screening squelches all that," - and the next shot shows no cassette in her hand, without time for her to get rid of it.
Continuity mistake: When Roz is talking to Martin in the cafe, she takes a cookie from the plate, but in the next shot she gives the brownie to Martin with the same hand and the cookie is nowhere to be seen.
Continuity mistake: At the beginning of the show, Frasier is sitting with Martin and Niles in Cafe Nervosa telling them about the radio play. As Marty says "we were a simple people", Frasier manages to open his briefcase, take out the script, put it on the table, and put his briefcase back on the floor and be sitting still - all in about 3 seconds. This just wouldn't be possible in real time.
Continuity mistake: Niles is in the police station talking to Frasier and as he says "What happened?" one hand is holding a coffee cup and the other is on his hip. As the shot changes, both of his hands are on the coffee cup. (00:13:20)
Roz, a Loan - S6-E9
Continuity mistake: While Roz and Frazier are talking in Cafe Nervosa, the whipped cream on top of her coffee changes position and amounts from shot to shot.
Legal Tender Love and Care - S8-E6
Continuity mistake: When Frasier is carrying Abbie's coat to his door, he is holding it about 10 inches below the shoulders, but as the camera changes to him coming through the door, he is holding it about 6 inches higher, with no time to shift position.
You Scratch My Book... - S2-E15
Continuity mistake: Honey puts both hands on Frasier's shoulders, but the next shot shows one around his shoulder and one around his back, with no time shift positions naturally. (00:18:55)
Continuity mistake: When Lilith and Frasier are in the hotel room, Frasier's shoes are on the floor by the chair, neatly arranged. When he says "that's very impressive, Dr. Sternin" and walks away, the shoes are not in the same position anymore.
Continuity mistake: Early in the show, when Frasier comes into the booth and gives Roz a muffin, the note from Bulldog has changed position on her clipboard even though no one goes near it.
How to Bury a Millionaire - S6-E7
Continuity mistake: While Niles is talking to Marty on his phone/intercom at the Montana, the sherry glass on the table changes positions several times.
Answer: In the last episode, they explained that Tossed Salad and Scrambled Eggs is a metaphor for the mixed-up people to whom Frasier dispenses his radio psychiatric advice.