The image points on your attack and player boxes were wonky.
Here's what I did:
1) Set your playerbox to mirror along with your character on turning left/right. This mirrors the imagepoints as well.
2) Created a new imagepoint for playerbox (imagepoint 1; you actually referenced it a few times without it ever being created) that was aligned on the ground and out a bit to the side.
3) Reset the attackbox origins to be at the center/bottom.capx