The Bad Son - S8-E3
Continuity mistake: When Niles and Daphne are on the couch talking about the meteor shower, she has his hand on his left knee and he is covering it with both of his hands. After he says "two horrible wrongs", his right hand is suddenly on his right knee, with no time for natural switch.
Continuity mistake: While Niles and Frasier are discussing Marty, we can see an old shoe on the footstool, but as the shot changes the shoe is gone and there is a newspaper there instead.
Continuity mistake: Eddie has been playing on Niles' couch, and the pillows are all over the place and there are a couple of other things on there as well. After Marty's chair arrives, Niles says to Frasier, "You have to take him back now," and suddenly the couch is all tidied up, with the pillows at the ends. A couple of shots go by and suddenly the couch is a mess again.
The Kid (2) - S5-E4
Continuity mistake: Roz and Frasier are in his kitchen talking and Roz has a bottle of water. In one shot we see the bottle cap on the counter, but in the next shot it has disappeared.
Continuity mistake: When Frasier and Niles are in Cafe Nervosa, Frasier is holding section of newspaper in his lap, with an inch or two showing on the table. He and Niles suddenly grab for their cellphones and the newspaper appears fully on top of the table.
Continuity mistake: Frasier puts the tuna on the coffee table for Mr. Bottomsley and the cat jumps up and starts to eat it - he is facing the couch. In the next shot we see Eddie come into the room and suddenly the cat has moved and is facing Marty's chair - without enough time for the change.
Continuity mistake: Frederick is visiting and sitting on Frasier's couch with headphones on, playing a Gameboy. Frasier pulls off Freddy's headphones, which then lie around his neck while Frederick continues to hold the Gameboy. In the next shot, the headphones and Gameboy are on the coffee table and Freddy is sitting quite a bit to the left of them.
Roz, a Loan - S6-E9
Continuity mistake: In the scene where Niles, Frasier, and Marty are talking about the spa, the spa products on the coffee table in front of Niles and Frasier keep changing position.
Continuity mistake: Niles goes to Frasier's apartment and meets Tom, the new station manager. Niles is talking to him with his hands clasped in front of him but in the next shot his hand are clasped behind his back.
Continuity mistake: Before Daphne's wedding in season 7, Mrs. Moon thinks Daphne's pregnant. In this episode she thinks Daphne is a virgin.
Continuity mistake: Marty picks up the head of the statue that was shot off and holds it for a couple of seconds. He then puts it down by the phone. After Daphne says, "All right, what's the plan?" we see it is in his hand again, and he puts it down again.
Agents in America, Part III - S2-E22
Continuity mistake: As Bebe says, "Darling, what you have is a fever" to Frasier, her hands are on the table in front of her. He says "what?" and the shot shows her elbows on the table and her hands are in the air, with no time for natural change.
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: When Roz and Daphne are in the kitchen, the tea cup turns about 45 degrees so we see much more of the flower pattern from the same camera angle. Neither of them touched it.
The Friend - S3-E11
Continuity mistake: Roz is showing Frasier some faxes in his booth at KACL - as she holds them they are folded over. As she says "are you nuts?", the papers are flat in her hand, no longer folded over, with no time for her to have changed them.
Continuity mistake: Near the beginning of the show, Poppy meets Niles at Cafe Nervosa. She has a black purse which she places on the table in front of her. During the scene, the purse is sometimes on the table and sometimes isn't, even though Poppy never removes it.
Continuity mistake: While Frasier, Roz, and Marty are at the table on the ship, Frasier is trying to write his speech. His pen switches from being in his hand to being on the table, several times, from shot to shot.
Continuity mistake: Late in the show, Frasier throws his notebook on the coffee table and it lies flat near the books. A couple of shots later, it is on top of one of the books, with pages flipped back. No one went near it in the meantime.
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.