Audio problem: When Prue is at the dentist, she grabs a guy and he says, "What, what did I do?" to his girlfriend, but his lips do not move.
Crimes and Witch-Demeanors - S6-E19
Audio problem: When Chris accidentally drops Phinks into the lava pit in Hell, he says "shoot", but his mouth is saying "shit." (00:21:10)
Audio problem: Baby Matthew is supposed to be screaming his head off, when Prue levitated the contents of her purse to cheer him up. But she turns him to the camera and he is smiling. (00:21:40)
Wicca Envy - S1-E10
Audio problem: When talking about the tiara with a security guard Prue's mouth stops moving mid sentence but the audio continues.
Audio problem: When Phoebe hits Cole over the head in the courtroom, the sound of something unfreezing is heard, but Cole wasn't frozen and Piper doesn't unfreeze the room until a few moments later.
Audio problem: When Evil Prue flings Piper and Phoebe back, you see Piper hit a pillar, but with Phoebe's voice of pain. When we see Phoebe fall behind a structure, we hear Piper's voice of pain.
Audio problem: When Piper, Paige and Phoebe run up to the attic to run from Shax, Piper says that they're about to find out if Paige is their sister, her mouth is shut when she is supposedly saying the sentence.
Sleuthing With the Enemy - S3-E8
Audio problem: When Phoebe fights with Krell in the mausoleum, the vial containing the Belthazor vanquishing potion is heard smashing, but after Krell is vanquished, Phoebe picks up an unsmashed vial and uses it to stage Cole's escape.
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.