Audio problem: When Selina returns home from work the first time and Miss Kitty comes in through the window, Selina pours some milk into the cat bowl and Miss Kitty begins to lap the milk (out of shot). Then, without a break in the lapping, Miss Kitty meows again as a cue for one of Selina's lines, but the lapping sounds continue underneath the meow. It's an open-mouth meow, too, and, as far as I know, no cat can both meow and drink at the same time.
Audio problem: When the mayor's baby is first stolen, the audience gasps in a very fake way. When the Penguin reveals his plan to steal the first-born sons to the party members later in the movie, they gasp the exact same sound effect. They actually do it a third time, later in Penguin's speech, but it's very quiet.