Mecanim Avatar Mask: Body Rotation and IK Problem

Hey! Iam currently trying to set up a grab upperbody animation for my character.
so ive set up a new “Upperbody Action” layer with an avatar Mask, weight of 1, blending to override and ik pass on.
my problem looks like this: Imgur

you see, when i turn on the ground mask (between the feats, I dont know how its called). the Punch goes in the right direction (front) but also the legs are moving with the punch. if i turn of the ground mask, the punch goes in the wrong direction but the legs are correct. also the movement is not working anymore when i turn on the ground mask:

how can i make both working: the legs and the punch in the right direction

here are more pictures from the editor:

(the third-last image is wrong, the weight is 1 not 0)

thanks!

Old post… buut… any answer? I’m in the same boat atm…