Corrected entry: In Alex's nightmare, he lands on the elderly Melman's right leg. When Melman mentions losing all feeling in his leg, he taps his left leg with his cane. (00:01:30)
Corrected entry: When the penguins are driving a car after they have escaped out of the casino, Skipper tells Kowalski to send a message to the chimps to meet them at the Hotel Ambassador. About 25 seconds later, when the camera is behind the car, you can see that the chimps were standing in the car all along. (00:13:25)
Correction: There was actually only one chimp in the car. That chimp was at the casino with them the whole time. The rest of the chimps were still waiting at the Hotel Ambassador.
Corrected entry: Dubois discovers an article about Alex missing from the zoo. In retrospect, he was never missing to begin with. In the first movie he was sent away to Madagascar as per pressure from animal rights activists. Furthermore, in Madagascar 2, one of the tourists, a New Yorker, recognized Alex in Africa. So almost a good number of people are aware of where he is.
Correction: In the first Madagascar, the crate that was containing Alex fell into the ocean, so technically, he would be missing. Plus at the end of the first Madagascar, one of the penguins said the boat was out of gas. So he would still be missing for quite some time. The old woman from the second Madagascar recognized Alex in Africa, so people are aware that Alex isn't missing. The newspaper Captain Dubois discovers could have very well been between the time the crate containing Alex fell into the ocean in the first Madagascar and the time the old woman noticed Alex was in Africa in Madagascar 2.
Correction: This is a dream. Everything is possible in the dreams.