I created a post in the 'Get Help' session of the forum on a peculiar behavior that was related to change of sprite images as part of an animation.
Specifically, when sprites that have been created using the :copy() method (rather than the .new([image]) function) once you use the :setImage(image), the sprite's size is changed to 0 height and 0 width. The sprite still has the correct image, but for some reason it's size are not translated to the sprite itself.
To avoid duplicating posts, for more details, demo and example code, please see this post.