My Button Mapping keeps breaking on my Space Navigator, even after I re-assign them.  In the attached image of the Button Mapping box, I don't have any of my functions to use to map the buttons along the LH side.  If I reasign them from the 3d connexion Properties box, they don't stay assigned, they become unavailable again after a short time.

This happened after upgrading to SW 2012.  Any ideas?