Audio problem: When Gaby's charity modelling event takes place and Susan, after being roughed up by John Rolland's mother after mistakenly accusing her of sleeping with her son, Tom starts talking but you can see him in the left corner of the scene without his mouth moving at all.
Revealing mistake: In the opening scene with Tom and Lynette, Lynette is standing in the doorway to her house but the interior in the background is different to the interior of her house. there is a blue wall in place where an open plan stair should be. (00:01:00)
Continuity mistake: When Lynette is sitting on the bench chatting to Claire in the park, you can see that Lynette has her hand on the pram, but when the camera angle is behind Lynette in other shots, she no longer does.
Continuity mistake: When Lynette sits down next to Claire on the bench at the park, Claire is wiping her hands with a tissue. Claire is not wiping her hands in the next shot, but in the shot after that, she is.
Every Day a Little Death - S1-E12
Continuity mistake: When Edie throws the urn of ashes at Susan after she discovered Susan burned her house down, you can see that there is nothing on Edie's left shoulder, but when the camera angle changes to behind Edie in the next shot, her shoulder is now covered by her cardigan.
Continuity mistake: When Lynette introduces herself to Claire at the park, the strap on her handbag is on her shoulder. When the camera angle changes to behind Lynette in the next shot, the strap has gone, and in the shot after that, it is back again.
Audio problem: When the Stagehand says "Come on, you're up!" to Susan before she is about to go on the catwalk at Gabrielle's fashion show, the words do not match his lips.
Continuity mistake: When Susan and Mike are lying on the floor in the kitchen, Susan says to Mike "You can pay the loan off by yourself" and Mike has his left hand on Susan's wrist, but in the next shot, he no longer does.
Every Day a Little Death - S1-E12
Continuity mistake: When Edie throws the container of Mrs Huber's ashes over Susan after she discovered Susan burned her house down, there is still some ash in Susan's hair and on her cardigan from a previous take.
Audio problem: During the dinner scene at the Scavo's home, Lynette tells Irina that her son Preston is "blinded by a piece of Eurotrash who would sell her own mother for a pair of designer jeans." When the camera changes to behind Lynette in the next shot, she can be saying the words "designer jeans" again, but this time with no sound.
Audio problem: When Lynette warns Anne to never lay a finger on her son Porter again, from behind Lynette's head she is still talking, but no words are coming out.
Audio problem: When Lynette slaps Anne Schilling across the face in the wash room, a slapping sound can be heard after her hand goes past Anne's face.
Continuity mistake: When Mike comes home soon and finds Susan in sexy lingerie in the living room, the laptop reads 0:00:36. Mike grabs Susan in his arms while she desperately tries to shut off the laptop, but only seven seconds later the screen reads 0:06:33. Then the camera switches again and the laptop reads 0:02:47 when Susan finally shuts the screen. (00:14:45)
Secrets That I Never Want to Know - S8-E1
Continuity mistake: When Gaby looks for her stepfather's car with Bree, Chuck takes over and drives it for them. But in past episodes the stepfather's Ford Focus was a two door model not a four door.
Continuity mistake: When Zach is in Julie's bedroom, he says to her, "And they buried her, to protect me" and you can see that Zach has his hand on his cheek. When the camera angle changes to behind Zach in the next shot, he no longer does.
Continuity mistake: Before the fight between Helen and Susan at the fashion show, Susan has a flower in her hair. There is no sign of the flower when Helen tears off part of her wedding dress, but when Susan says "What?", the flower is back again.
Continuity mistake: When Gabrielle asks Angie if she would like to meet Heidi Klum at the modelling agency, the magazine Gabrielle is reading is open, but when she says "Sure, she's an old friend", the magazine is closed.
Continuity mistake: Lynette is giving a speech during Renee's wedding. In some shots, she holds the microphone in her right hand and a glass of wine in her left hand. In other shots, she holds the microphone in her left hand and a glass of wine in her right hand. (00:32:40)
There Is No Other Way - S2-E16
Continuity mistake: When Susan reveals her feelings in the operating room, the face mask Dr Ron is wearing covers his nose and mouth in one shot, then not his nose in the next, then his nose and mouth again in the next. (00:38:30)
Color and Light (a.k.a. I Must Be Dreaming) - S2-E7
Continuity mistake: When Gaby goes outside to ask for help with her dress, you can see that the door is open when she leaves, but a couple of shots later the door is closed, despite Gaby not being near it.
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.