Using multiple physics constraints - they wobble!

I have two actors, ActorA and ActorB. Attached to ActorB I have a component (Component C). I have constrained C to B with a physics constraint (rigid), and then constrained B to A with a physics constraint. If I just constrain A to B, it works fine. Same for B to C. However, if I constrain A to B and then B to C, the A to B constraint wobbles like crazy, like its made of really soft rubber. If I move really slowly, it is ok, but anything even slightly fast and it bounces around.

Both physics constraints are attached to ActorB, with the staticmesh as the parent.

Does anyone have any tips? Am I doing something wrong?