Audio problem: When Mac and co. enter the basement of the house in Queens (the one where the third woman was found) the record player lifts off its needle and moves to another spot on the record, cutting off the sound for a second. However, the music starts again slightly before the needle hits the record.
Audio problem: Season 5, episode 17 "Green Piece": When Stella is typing on the Apple keyboard she hardly lifts her fingers from the keys, yet we hear a loud clicking sound. That type of keyboard doesn't make that kind of sound, unless you pound the keys with great force. Also, the clicking sounds don't match up with her keystrokes.
Audio problem: During the sequence where Lindsay is telling them about the tape with the lipstick on it, they show a man tying up a woman. You hear the sounds a woman would make if she was muffled by a gag (tape) on her mouth as she's being tied/struggling throughout the scene, but her mouth doesn't get taped until the end of the scene.