As has beeen said, you should to select an actor that contains geometry. Selecting the hair from the document window, using the cursor should ensure this. If more than one actor contains geometry, you can use "Add element to deforme" from the Mags Properties to add the influence of the magnet to more actors. One thing that will stop a magnet from affecting an element is if that element has "Bend" turned off. So check in the hair's Properties for the actor[s] that contains the geometry to make sure that Bend is turned on. P.S. MirrorMags is not a Python script, it's just two magnets and a prop, with some ERC to controle the magnets in a symetrical way. There are some Python scripts to mirror magnets, I think there is one in PhilC's Poser Tool Box, and I also seem to remember seeing a free one somewhere (try asking in the Python forum).