Dforce Magnet refuses to move

wmiller314

I'm working on a scene where I want to use the dforce magnet to lift the hem of a skirt. I use geometry selection tool to select the vertices, then in my time line move the magnet up to where I want, and when I check this in the time line slider, everything works fine. When I click render, instead of the fabric moving, the dforce magnet gets long and the skirt hem remains exactly where it was. Anybody know what I'm doing wrong?