I see the problem: you're setting it so that the EXPLOSION is spawning explosions. Generally, when spawning objects it's safest to use the System - Create object action. Set the coordinates to Spinna.X, Spinna.Y, and you should get what you're looking for.
Also, the line that says "On animation 'Explosion1.AnimationName' finished"... maybe I've just never seen that usage before, but I don't think that'll do what you want. Unless that's literally the name the of the animation. <img src="smileys/smiley17.gif" border="0" align="middle" />