hi, I tested an example with Algodoo. The system move alone, but it's possible it's an error. Look position (X) with graphical function. In one direction or other direction the position is moving.
Another Algodoo scene, the system destroy 8000 J in 20 seconds. No friction from air or solid. Like the system can be done in reverse mode this would say it can create energy. Maybe it's an error on the scene, can you test ? The perpendiculary force seems to be not perpendiculary for each force, maybe the sum is not 0 for the perpendiculary force.
I reduced mass and attraction for increase precision (frequency is always to 1200 Hz but like the attraction is lower, the system move very slowly). The energy decrease with the same proportion. I think it's the force from wall (circle) that is not perpendicular to the force of attraction. The center of mass is in the center of circle but the center of gravity is not in the center of the circle, it changes all the time and it is more and more at outer circle when it approached the bottom (where the fixed mass is). The force from wall works in this case. Nobody has test ?
A video of an example (no friction of air, no friction on solid, frequence at 1200 Hz):
http://www.youtube.com/watch?v=rfYZcRUxjAk&feature=youtu.be
Here another example energy of ellipse increase.