Near the beginning of the episode, when Daphne hastily cleans up the breakfast dishes, she drops Martin's chocolate éclair ("longjohn") in a glass of orange juice. Two cuts later, the éclair disappears and isn't seen again for the remainder of the scene.
When Frasier sends the contractor to Daphne's room, he says, "It's just down the hall, first door on the right." But in fact, Daphne's room is the first door on the left.
Martin tells Frasier that he couldn't find the TV remote control the previous night. Frasier responds by asking, "What was it like in the old days when you actually had to get up to change the channel?" TV remote controls became more less ubiquitous by the mid-1980s; as Frasier was born in 1952, he would have had plenty of experience as an adult with non-remote-controlled TV sets.
Frasier sends his contractor to Daphne's room and he's never seen nor heard from again.