Other mistake: When Bree goes to talk to Eddie Orlofsky's mother, she introduces herself as "Bree Hodge." However, she proceeds to talk about how Eddie likes her daughter Danielle, but her daughter "doesn't return his feelings, she spends most of her time with the other cheerleaders." In the scene before, Eddie had also mentioned that he liked a girl "from school." The problem is at the time that Danielle was in high school, Bree was not "Bree Hodge", but "Bree Van de Kamp." She hadn't even met Orson Hodge then.
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.
Continuity mistake: At the end of season 5, Lynette finds out she's about 6 weeks pregnant. At the end of the same episode, they do a "Two Months Later." In Season 6, Episode 1, Tom says after an argument with Lynette "Only 8 and a half more months." Lynette should be in her second trimester by then, with at most 6 months to go.