In case you bump into this dark IK solver matter of ikSpringSolver, first time you probably had a problem with some kind of double IK plane rotation. This is due to a bug, according to Juss Rig It blog since Maya 7.0.
Unparent the joint chain and keep it under world identity (origin) group with scale of your rig connected. Parent constraint the top joint of this chain (translate + rotate + offset) to its desired parent from the rig. Keep the handle parented anywhere you want or also use parent constraint.
Also, as with ikRPsolver, you have to connect the pole vector values to rotate its plane (usually by making pole vector constraint).