Does she do it when you are home or just when she is alone?
If she does it when you are home when she poops praise her and then if she goes for it (sticks her nose in it, paws at it, etc.) tell her "leave it." When she does praise her and give her a treat. Then pick it up and dispose of it. This will teach her that its better to leave it because she gets a tastier treat.
Thats all I got...but I'm sure others will have more suggestions!