I've noticed an issue with the image editor. If it's recent or not I don't know.
If I make a sprite, import an image to the default animation, and duplicate the animation to make a identical (but flipped) animation, the animation will unflip itself when I close the editor or switch to another animation.
Original capx where I found the problem (originally a project, but saved it as capx)
The problem seems to stem from duplicating an animation where the images were imported.
In the pendulum_problem capx, the "Sprite" objects animations were handled like previously mentioned, it has the same problem.
The "Sprite2" objects animations were made separately (i.e. 'not' duplicated) and the problem does not occurr.
The "Sprite3" objects animations were duplicated AND using the pencil tool instead of importing an image, and the problem does not occurr.
EDIT: Corrected the explanation of "Sprite3"
EDIT 2: Added [r97] to topic title.