The library is really awesome.
With the newest version from github i get a strange bug when i flip the player. Without flipping everything is normal, but as soon as i flipX the player, the positions of the images are messed up. The drawing of the bones is upsidedown, but the animation is fine.
I guess i forgot something, but i also didnt get your test working when i flip the player with flipX().
I'm using Slick2d, but i also tested the Java2d tests, there the bones are always correct, just the images are not in position.
I hope someone can help me and thank you very much.