That’s looking better all right!
Hmm, the next step might be to try to export the same thing using a different static pose. If that works properly, then try mixing and matching: apply the animation for pose B onto the model for pose A, and vice-versa. They should apply correctly, and after binding, should move the model from the rest pose to the anim pose you have applied. If that doesn’t work, then I think the vertex influences must be wrong.
David