Corrected entry: In the scene when Carl and Allison are in Lincoln Nebraska skeet shooting, Allison has a double barrel shotgun and accidentally fires once into the ground, on her second shot she hits the skeet then turns around to the onlookers who all dive for cover, nobody else has shot in this time so it would be obvious to all that her shotgun was empty and completely safe.
Corrected entry: When Carl is in Blockbuster at the beginning of the movie, he picks up 300 with his right hand and keeps walking. When he looks at Transformers, he is still holding 300 in his right hand, but then the camera zooms in on him picking up Transformers with his right hand and 300 is nowhere to be seen.
Corrected entry: When Carl arrives at his apartment, it says "Allen" (his second name) on the door. However, when he comes out of his apartment later on in the movie, just as his neighbour asks to put up some shelves, the sign is gone.