Continuity mistake: The 1st scene where Harry blows a horn in Anna's ear, she chased him out of the room and her blanket was thrown over on the RIGHT SIDE, but if you look close when she goes to close the door the blanket it almost all the way off the bed on the LEFT SIDE. (00:01:35)
Continuity mistake: When Tess is cutting the underwear off of Harry's head, she leaves the scissors on the counter away from the pile of the pieces of the underwear. Later you can see that it is in the pile of underwear. (00:11:25)
Continuity mistake: The way Tess holds the notepad, to show grandpa the message, changes between the shots. (00:11:30)
Continuity mistake: Once Grandpa takes the underwear off Harry's head and sets it on the counter, it continually moves. Originally it is at the edge, draped over a little bit. Next it moves inward a little. After Mom shuts off the power, it is almost halfway on the counter. (00:11:40 - 00:13:00)
Continuity mistake: When Anna is arguing with her mom in the kitchen, she mentions Jake. When she does her entire body position changes completely between the instant camera cuts. (00:16:30)
Continuity mistake: When Anna is pulling Tess in her bed she loses her grip and falls to the floor. As Anna falls you can see her bare foot come up, but in the previous shot she was wearing socks. (00:25:15)
Continuity mistake: When Anna and Tess are on the staircase checking to see if the coast is clear, we see Harry and Grandpa eating cereal, where Harry's cereal box is seen from the back. In the next shot of them, it's seen from the front. (00:27:50)
Continuity mistake: When Pei Pei calls for her mother, she comes from the kitchen. She sees Anna and Tess and tries to escape by going back through the door she came from, but when the camera cuts back to her, she is about to enter the other door. (00:49:48)
Continuity mistake: At the wedding rehearsal, when they have just returned to their own bodies, Anna picks up a glass of water to toast but once she raises it, they feature a shot from behind her in which the glass and the liquid in it has completely changed. (01:26:36)
Continuity mistake: When Dr. Coleman wakes up in Anna's body, as Lindsey Lohan exits her room her bedroom door is still removed, but a few seconds after she runs out of the room after Harry the door has been re-attached.
Audio problem: When Anna and Tess go back to the Chinese restaurant to ask them about the fortune, Pei Pei calls her mother to them. When her mother responds to one question you can hear her talking but her mouth is no longer moving.
Continuity mistake: When Anna (Tess) is in Anna's room in her robe with her hair up, she is looking for the fortune in Anna's pants pocket. She finds it and drops the pants, but in the next shot they show a close up of the fortune and Anna still has the pants in her hand.
Continuity mistake: Right after Anna and Tess leave House of Chang, Tess' organizer goes off reminding her about a parent/teacher meeting. "Tess" freaks out, and "Anna" puts her hands on "Tess'" face to calm her down. The organizer has disappeared.
Continuity mistake: When Anna and her Mom are first together in their switched states: "Anna" is trying to wake up "Mom" and on the wall, left to the bed, we see this ugly turtle wall ornament. In all shots subsequent, however, it's disappeared.
Audio problem: During the audition song when the drummer first looks at Anna wondering why she isn't playing, his sticking is out of synch with the drumming.
Continuity mistake: At the beginning of the movie, Ryan's hair is short. In the scene where he, Anna and Tess are talking about why Anna was riding on the back of Jake's motorcycle, his hair is several inches longer. At the wedding rehearsal his hair is short again, the same length it was at the beginning of the film.
Continuity mistake: When "Pink Slip" are singing "Ultimate" right at the end, you can see a small group of girls clumped together behind Anna and her girlfriends, and in the next shot they are completely gone. It's impossible for them to have moved entirely out of eyesight in those few seconds they are off camera.
Audio problem: When the band Pink Slip is performing their song at The House of Blues, near the beginning of the song, Anna's two band mates are looking at her and wondering why she isn't playing. Maddie (the lead singer) is looking at Anna and singing, but Peg (the other guitar player) is looking at Anna and not singing. However, in the song, you can hear someone singing a harmony note opposite the main melody. How could that happen if Peg wasn't singing?
Continuity mistake: Anna's friend, the lead singer in the House of Blues performance, had not very much blush on, but an overload of eyeshadow on at the rehearsal, but when she got to the House of Blues she had an overload of both. When they were actually playing and after, the blush was cut back on again.
Continuity mistake: After Anna gets out of her second detention, when the things fall out of her bag, first you can see that the bag is still on her shoulder but her bag just turned upside down. In the next shot when you see all the things on the ground, you can see the bag touching the ground. When the shot goes back to Anna you can see the bag is on her shoulder again and upside down again.
Answer: You need to think back to the poem... "A journey soon begins, its prize reflected in another's eyes. When what you see is what you lack, then selfless love will change you back." It says a journey SOON begins, not immediately, and it says "WHEN what you see...change you back". Basically the switch happens SOON, the switch back happens IMMEDIATELY.