Problems with 2D Sprite Animation

Good morning. I've a problem with my 2D sprite animation. The thing is really simple, I want to animate a coin. I have the sprite sheet with 9 different images for the animation, the Animation component in the Game Object and the Animation made. But it doesn't work. The animation doesn't play, nor in the animation panel, nor in the scene while is playing. If I look in the Sprite Renderer component of the Game Object, the image doesn't change while the animation is playing. I've tried everything. Any help will be helpful. Here are some images:

I use NGUI system for the GUI side of my game, and the Game Object is inside NGUI structure. But I tried move it outside that, and nothing...