Continuity mistake: In the scene where Bree and Lynette are talking about nannies, Lynette is in the back seat strapping her baby daughter into the car seat. In the shot facing Bree, Lynette takes a baby toy lying on the back seat and hands it to her daughter, but in the next shot facing Bree, the toy is back on top of the seat where again Lynette hands it to her baby.
Audio problem: The opera singer seen at the beginning at the episode is dubbed. His lip movements don't quite match the tune.
Sunday in the Park with George - S1-E21
Continuity mistake: When Bree is out for dinner with George, the scene starts with a close up of her eating with her fork in her right hand. It then cuts to a wide shot of her suddenly holding her fork in her left hand, and then she switches it to her right hand.
Audio problem: Season 2, Episode 17: "Could I Leave You?" - Veronica's son's lip movements do not match when he tells her that he's thirsty.
You'll Never Get Away From Me - S2-E3
Visible crew/equipment: When Phyllis leaves in the taxi, a boom mic is reflected in the taxi's rear window.
Color and Light (a.k.a. I Must Be Dreaming) - S2-E7
Visible crew/equipment: Right at the beginning of the episode, we see a woman drop her daughter off at a strangers house. When the front door opens, a camera crew is reflected in the brass door knocker.
Color and Light (a.k.a. I Must Be Dreaming) - S2-E7
Continuity mistake: When Julie finds out about Susan and Karl sleeping together, the tightness of Susan's dressing gown changes several times throughout the scene.
Continuity mistake: When Bree grabs the twin's toy keyboard, she grabs it and holds it at a downward angle. But in the immediate shot she is suddenly holding it at an upward angle.
Continuity mistake: When Lynette starts talking to Andrew, her car door suddenly goes from closed to open between shots.
Continuity mistake: When Julie is tutoring Austin, he takes out a beer can, drinks it, crushes it and puts it down on the desk. A couple of shots later when Julie stands up, the beer can has rotated itself slightly without Austin touching it.
My Heart Belongs To Daddy - S2-E4
Continuity mistake: When George is eating watermelon with Bree, the position the watermelon on his plate and the salt shaker on the table change between shots before George or Bree even touch them.
Continuity mistake: Season 3, Episode 6: "Sweetheart, I Have to Confess" - When Gabrielle suggests that her and Carlos don't go through with their divorce, her head is resting on Carlos' chest. But in the next shot, it isn't.
Your Fault - S1-E13
Visible crew/equipment: After the scene where Mr and Mrs Rowland speak with Gabrielle, a crew member is reflected on the side of Paul Young's car as he pulls into his driveway with Zach.
Continuity mistake: When Bree is at the restaurant by herself, she is wearing a ring around her neck on a chain which constantly moves position throughout the scene.
Visible crew/equipment: When Edie is talking to Julie and Austin about their sex life, the pole of a boom mic can be seen reflected in the window behind Edie.
Continuity mistake: When Bree is talking to Mike in hospital, the position of her roll neck jumper on her right shoulder changes constantly throughout the scene. In some shots it's rolled down, in some it is rolled up.
Continuity mistake: At one point in episode 1.2 ("Ah, But Underneath"), Susan looks at the note used to blackmail Mary Alice and we can see that it has been folded twice and become somewhat crumpled. Two episodes later in "Who's That Woman?" (1.4) when the girls show the note to Paul, it is almost perfectly smooth with a single horizontal crease.
Other mistake: Bree is drinking wine with Karl, but before in other episodes and season and episodes and seasons after, she sternly says she does not drink because she was an alcoholic.
Mama Spent Money When She Had None - S5-E14
Continuity mistake: In an early scene Bree pulls up in a Lexus four door and the camera lingers on the car. But later in this episode she brings the same car home as a gift for herself.
Answer: Kayla was sent away in episode 16 (The Gun Song) in season 4, after falsely accusing Lynette of child abuse. She now lives with her grandparents - probably Nora's parents.
I'm curious why we never see her again, why she never talked about, and why Tom never mentions visiting her.