Audio problem: When Tina is tied to the palm tree with the bomb armed and Ipkiss is fighting with the goons. Ipkiss fights with Dorian and punches him over and over with Dorain on his back. The punching sounds are VERY obviously off from the action.
Audio problem: After The Mask gives his "Oscar winning speech" and Dorian sticks a gun in his face, "You're not going anywhere" can be heard. No one says this and was poorly recorded.
Audio problem: In the scene where Milo jumps at the cell window to save Ipkiss, Stanley says "good boy," but his mouth doesn't move. (01:13:00)