DzQuat question

I have the following 2 scripts that find a node (merlins skull) and rotates it 90 degrees. the second uses an overloaded version of DzQuad

var nNode=Scene.findNode('MRLN_MSSkull_7542');

nNode.setLocalRot(DzQuat(0,1,0,Math.PI/2);

var nNode=Scene.findNode('MRLN_MSSkull_7542');

nNode.setLocalRot(DzQuat( DzVec3(0,1,0),(Math.PI/2)));

As you can see from the attached image, they give different results. 

image one is starting position, two is script 1 and three is script 2. (script 2 is how I would expect it to behave.)