setLockAxis for Node Mouse Look questions

How does setLockAxis work in conjunction with NodeMouseLook and then KeyNodeRotateLeftAction?

I have the following code being used at the moment but it makes the rotation behave strangely.

        mouseLook.setLockAxis(new Vector3f(chaser.getCamNode().getLocalRotation().getRotationColumn(1).x,

I have split the xz plane rotation and the yzplane rotation on to different nodes (ie the up/down rotation rotates the camera and the left/right rotation rotates my player). This might conflict slightly and get weird results.

If I comment this part of the code out it behaves perfectly. But by doing so, do I open up avenues to other problems?