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.
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.
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.
Chosen answer: Her agent/manager negotiated a special billing as part of her contract. It distinguishes her from the rest of the cast, probably when she became a producer on the show.
JC Fernandez