The latest version of bones? I re-downloaded off your website in the link "Bones can be downloaded here". All the files seem to be last modified in 2014 so perhaps I am not downloaded the right project. Or maybe I am and I am just not seeing the modification date. Anyways, I tried that version and nothing changed. It may be important to note that when I start the program up, the actor wasn't facing me properly. I modified the quaternion to make him start in the proper orientation with this quaternion:
Quaternion fixer = new Quaternion().rotateX((float)-Math.PI/2);
fixer.rotateY((float)Math.PI);
I doubt the quaternion has anything to do with it though, because if I don't modify your code it still produces the exact same animation.