Audio problem: When Kevin and his crew of thieving little people land in the Middle Ages, Randall informs Kevin that they made all of what's surrounding them, trees, shrubs, bushes etc. Kevin's reply is "Phew, that's not bad" He says this without opening his mouth. This was looped into the film later on.
Audio problem: When Perseus starts to swing his rope at Pegasus, the rope is absurdly loud, and is obviously just the same recorded "whoosh" sound repeated four or five times.