Rope 'jumps' when a particle is added or removed

[Wilbert]

I've created a system with four Obi Rope cables and a hook for a crane simulation.
When I change the length of the rope, each time a particle is added or removed the rope makes a jump.
See video: 

I'm using this code to change the length of the cables:

Code:

 float flCableLength = rsc.rpcCablesOuter[0].GetComponent<ObiRope>().RestLength + Input.GetAxis("Hoist") * flHoistSpeed;
       foreach (ObiRopeCursor rpc in rsc.rpcCablesOuter) rpc.ChangeLength(flCableLength);

How can I prevent the 'jumping' ?