I'm not quite sure I saw what you problem was. The only thing I can think of is that you had the "Down Button" action ticked, which allowed Wario to fall through the platform when you pressed down and jump at the same time.
I edited the .cap just a little. I changed the controls, so now you control an invisible "Player" and have Wario always at his position. The "Player" handles collisions much better, and Wario's animations are not jerky when he moves. I recommend using a "Player" whenever you make another game.
I'm not really sure I solved your problem, so let me know if you still are experiencing that problem, and I will try to fix it! :)