Audio problem: Right after Helga is standing behind the "ARNOLD" on the pavement, when she says "Hey Arnold", her lips move as if she's saying it slowly (this is fixed in the 4th season).
Audio problem: The computer's voice says "golf shoes" while the screen says "golf cleates".
The Raffle - S3-E3
Audio problem: When Kel breaks the TV, the sound is a very clear overdub to make it clear the TV is broken. (00:08:15)
Dick and the Other Guy (2) - S3-E23
Audio problem: When Liam is performing karaoke at the end of the episode, his mouth is not even moving for some of the lyrics, and there aren't any vocal tracks on the song, because only the instruments are heard when he abruptly stops singing to admonish the crowd for trying to leave during his performance.
Midori no chikyû wa makasetoke - S1-E2
Audio problem: In the hangar scene at the beginning, Goat is talking to Akito. Seiya Uribatake in the background is arguing with his fellow mechanical worker about the reparations to the Aestivalis. The conversation happens in the back of the hangar and it is meant to be strong background noise, annoying enough to prompt Goat's reaction, but in the English dub it is so strong that quite literally most of the main dialogue is nearly inaudible because of it. The dubber also adds a surprised/scared "waah" at the end when Goat cuts him off, but that is incredibly delayed compared to the reaction of the character on screen. (00:02:35)