I had a similar problem with my animations. I think it has something to do with the setup mode.
I have a function that resets my animation to the first frame so I can trigger it with another event or function
private function resetAnimationPosition() : void
{
skeleton.state.setAnimationByName( 0, "introAnimation", false );
skeleton.state.apply( skeleton.skeleton );
skeleton.state.clearTrack( 0 );
}
Good luck