How do I play an animation with a single button press?

I'm not sure if this is a bug or if I'm doing something wrong, but I can't get an animation to play through.

I have it set to trigger on pressing the Z key and to start the "StandingAttack" animation from the beginning. But the animation only plays while the button is held down. If I don't hold the button down, it will pause and hold on an animation frame.

Kind of hard to describe but you can see what I mean if you try it out.

EDIT: dropbox.com/s/9tcy7203p5n1csp/caves%20of%20auld.capx Here's a link to my .capx so you can see what's going on.

change to

Thank you very much korbaach, that's fixed it.