just saw the capx.
your issue is that you are using the player as player AND playerImages, and you need to create an invisible object.
The manual recommends: "For the most reliable platform movement, it is recommended to use a invisible rectangle sprite with no animations with the Platform movement. Then, the animated player object can be positioned on top of that. Otherwise, the changing size and collision polygon of the object as its animation plays can interfere with the Platform movement's floor, wall and slope detection, causing a shaking or glitchymovement."
this tutorial will solve all your issues:
scirra.com/tutorials/243/building-a-platform-game-a-beginners-guide/page-1