Just to cover the basics, why don't you scale the zone to something rather large, large enough to cover both figures.  And add every actor of the hair figure as well for the mag to deform.  Better yet, is it possible if you can do this without conforming the hair, and only the hair figure in the scene.  And make sure the group box in the magzone property tab is unchecked.  It also doesn't hurt to have these checks done in a freshly started Poser in a freshly turned on computer, if you know what I mean :)

Alternately, You can also import the hair object and mess with it instead of the figure.  Export out the morphed hair and use it as a morph target.

If all else fails, as a last resort, import the hair object and use the setup room to create a new hair figure using the donor bone from other similarly styled hair figure.  Or if you are comfortable with doing it by editing cr2, whichever method you prefer, create a new figure and see if that solves this mystery magnet problem.