End Of Days - S7-E21
Audio problem: When Faith is in bed and talking with Buffy, she says, 'and no one else can feel it' her lips don't sync with what she's saying.
As You Were - S6-E15
Audio problem: When Buffy and Riley are fighting the Suvolte demon at the dam, Buffy calls out Riley's name at some point during the fight. Her lips don't move.
Audio problem: When Jenny and Giles are talking and Jenny is talking about the festival, they walk behind a drinks machine and then her lips don't match up with what she says.
Audio problem: When Anya comes in from helping the potentials get in the car, she says that Molly is in the trunk. She then says something along the lines of "I'm surprised at how compact Molly is," as she walks away with Willow, but her mouth doesn't move.
Audio problem: When Joyce comes downstairs and comments on the breakfast Buffy made, Dawn says 'Oh, Buffy helped,' but her mouth doesn't match what she's saying.
Once More, With Feeling - S6-E7
Audio problem: During Buffy's first song she does a spinning kick to a vampire's face as she sings, "I've been making shows of trading blows, just hoping no one knows." But as she spins, her lips are not moving.
Audio problem: When Warren, Jonathan and Andrew break into the museum to get the diamond, Warren makes a hole in the glass, then pushes it through, but when it lands, it sounds like plastic, not glass.
Out Of Mind, Out Of Sight - S1-E11
Audio problem: When Cordelia is tied to the chair at the end of the episode from a side view you can see her mouth 'Marcie' but can't hear it and in the front shot she says 'Marcie' again.
Audio problem: At the start of the episode when Buffy and Dawn are with Joyce in the hospital room, Dawn starts eating jelly, and when Joyce starts speaking you can see in the left hand corner of the screen Dawn talking, but no words are coming out.
Storyteller - S7-E16
Audio problem: After Anya and Xander sleep together again, Anya says "I think, maybe we're really over. Which - it's good, right? I mean, now we can move on." When she says "Which - it's good", her lips don't match what she's saying.
Once More, With Feeling - S6-E7
Audio problem: In the episode 'Once More, With Feeling', when Anya sings her first few lines of the song 'I'll Never Tell', you can still hear Xander talking about omelettes in the background, but for the last few lines he speaks (from 'I could do an omelette' onwards) you can see over her shoulder that his voice is dubbed. (00:13:10)
I Was Made To Love You - S5-E15
Audio problem: When Spike arrives at the magic shop with a burning blanket over his head, he throws it to the ground and stomps on it, yelling, "Fire! Fire!" As he yells "Fire! Fire!" however, his lips aren't moving.
Audio problem: Jenny prints off the translation for the Ritual of Restoration from her computer, then spots Angel sitting across the room from her. As she gets up and starts walking towards him the sound of the printer can be heard but the paper has already finished printing.
Once More, With Feeling - S6-E7
Audio problem: In the final song "Where Do We Go From Here", you can hear Spike still singing even after he has apparently stopped. He and Buffy continue singing until after the line 'When do the trumpets cheer'. It is noticeable because James Marsters sings the word 'cheer' slightly out of sync with everyone else.
Audio problem: When Willow and Jenny jump in Cordy's car, Cordy mentions that she saw "these things coming at me!" However, her mouth isn't moving for the last few words.
Out Of Mind, Out Of Sight - S1-E11
Audio problem: When the invisible girl writes "Listen" on the chalkboard, the chalk sound effects don't match the writing for the last few strokes. (They're about a half-second too "early.").
Out Of Mind, Out Of Sight - S1-E11
Audio problem: When Cordy and Buffy are talking and Cordy says "Well it beats being alone all by yourself, " pay attention. It's clear that part of the line was dubbed in, as there is a very hard cut between the words "Well" and "It."
Chosen answer: He had larangitis and because of the shooting specifications they had to have him shoot the scene with a bad throat, they then re-recorded his lines and dubbed them. At various points during the scene and indeed the episode you can see him touch his throat or rub it.