The Southern Air Temple - S1-E3
Other mistake: When the gang is in the Hall of Statues of Past Avatars, Katara points out the avatar cycle pattern of statues and Aang zeroes in on Roku's statue. The earthbender avatar statue next to Roku is of an unknown man with a sword, not Kiyoshi. (00:12:50 - 00:13:35)
Other mistake: In the voice cast list, the Groom's Father appears twice - with two different voice actors - and the Groom's Mother is not even listed.
It's a Mad, Mad, Mad Hotel - S1-E12
Other mistake: In the episode "Its a Mad, Mad, Mad Hotel", when Esteban has his dream of becoming rich and London becoming his "Bell Girl", he calls the hotel "Hotel Esteban, but London's uniform still has a "T." When it cuts there is an "E" on the front desk.
Gopherville - S1-E1
Other mistake: In "Sock Safari", when Toopy finds a red thread, his left hand with his glove disappears instantly.
Other mistake: When Stacy sees Zoey's designed backpacks for the first time, she uses her camera to take pictures of them. In one shot, a close up of the camera display is shown and the message "CF card full" is on the display and yet the camera still makes "click" sounds as Stacy seems to take pictures. (00:10:22)