After all 5 characters climb out of the quick sand they are all covered in quick sand. In the following scene, all 5 are clean with no evidence of any quicksand on their clothes.
When Dora and her friends are outside the city gates, the moon in the sky is half-full. When they enter, it's completely full.
Early in the film, Dora mentions being attacked by pygmy elephants. These animals are indigenous to the island of Borneo in Southeast Asia, not South America.
When Dora gets her backpack stuck in the door of the bus, an Australian school speed limit sign can clearly be seen in the background, as well as other distinct Australian signs in this and other scenes at the school - they are characterized by their bright orange borders and fluorescent yellow backgrounds.