Use a Vanessa rig, and don't look back:

http://home.mindspring.com/~the-plum...%20Machine.htm

http://www.rcuniverse.com/forum/m_70.../tm.htm#708060

As explained above, I believe that the problem you have is related to the natural instability of the situation where the CG is above the pivot point (skin of the wing in contact with the balancer).

As the schematic shows, the situation in which the CG hangs from a pivot (Vanessa), is self-stable.

Regards