[Closed] assign multiple position constraints targets !?

I am trying to make an automated rig and I’ve hit a wall with adding multiple position target objects to a position constraint controller. Adding the first one works perfectly but all the following ones are returning false. Here is the code:

--create sample objects
theBox = box()
thePoint1 = point()
thePoint1.pos = [50,50,0]
thePoint2 = point()
thePoint2.pos = [-50,0,0]

--the constraint part
pc = position_constraint()
theBox.position.controller = pc
pc.appendTarget thePoint1 50.0  -- this line works perfect
pc.appendTarget thePoint2 50.0  -- this line returns false and does not add the object !?

Am I missing something here?